- A browser is an application program that provides a way to look at and interact with all the information on the World Wide Web. The word “browser” seems to have originated prior to the Web as a generic term for user interfaces that let you browse (navigate through and read) text files online.
Technically, a Web browser is a client program that uses HTTP (Hypertext Transfer Protocol) to make requests of Web servers throughout the Internet on behalf of the browser user. Most browsers support e-mail and the File Transfer Protocol (FTP) but a Web browser is not required for those Internet protocols and more specialized client programs are more popular.
The first Web browser, called WorldWideWeb, was created in 1990. That browser’s name was changed to Nexus to avoid confusion with the developing information space known as the World Wide Web. The first Web browser with a graphical user interface was Mosaic, which appeared in 1993. Many of the user interface features in Mosaic went into Netscape Navigator.
A browser is a software application used to locate, retrieve and display content on the World Wide Web, including Web pages, images, video and other files. As a client/server model, the browser is the client run on a computer that contacts the Web server and requests information. The Web server sends the information back to the Web browser which displays the results on the computer or other Internet-enabled device that supports a browser.
The two most popular browsers are Microsoft Internet Explorer and Firefox. Other major browsers include Google Chrome, Apple Safari and Opera. While most commonly use to access information on the web, a browser can also be used to access information hosted on Web servers in private networks.
- A buffer is a data area shared by hardware devices or program processes that operate at different speeds or with different sets of priorities. The buffer allows each device or process to operate without being held up by the other. In order for a buffer to be effective, the size of the buffer and the algorithms for moving data into and out of the buffer need to be considered by the buffer designer. Like a cache, a buffer is a “midpoint holding place” but exists not so much to accelerate the speed of an activity as to support the coordination of separate activities.
This term is used both in programming and in hardware. In programming, buffering sometimes implies the need to screen data from its final intended place so that it can be edited or otherwise processed before being moved to a regular file or database.
A temporary storage area, usually in RAM. The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device.
Because the processes of reading and writing data to a disk are relatively slow, many programs keep track of data changes in a buffer and then copy the buffer to a disk. For example, word processors employ a buffer to keep track of changes to files. Then when you save the file, the word processor updates the disk file with the contents of the buffer. This is much more efficient than accessing the file on the disk each time you make a change to the file.
Note that because your changes are initially stored in a buffer, not on the disk, all of them will be lost if the computerfails during an editing session. For this reason, it is a good idea to save your file periodically. Most word processors automatically save files at regular intervals.
Buffers are commonly used when burning data onto a compact disc, where the data is transferred to the buffer before being written to the disc.
Another common use of buffers is for printing documents. When you enter a PRINT command, the operating system copies your document to a print buffer (a free area in memory or on a disk) from which the printer can draw characters at its own pace. This frees the computer to perform other tasks while the printer is running in the background. Print buffering is called spooling.
Most keyboard drivers also contain a buffer so that you can edit typing mistakes before sending your command to a program. Many operating systems, including DOS, also use a disk buffer to temporarily hold data that they have read from a disk. The disk buffer is really a cache.
- In most computer systems, a byte is a unit of data that is eight binary digits long. A byte is the unit most computers use to represent a character such as a letter, number, or typographic symbol (for example, “g”, “5”, or “?”). A byte can also hold a string of bits that need to be used in some larger unit for application purposes (for example, the stream of bits that constitute a visual image for a program that displays images or the string of bits that constitutes the machine code of a computer program).
In some computer systems, four bytes constitute a word, a unit that a computer processor can be designed to handle efficiently as it reads and processes each instruction. Some computer processors can handle two-byte or single-byte instructions.
A byte is abbreviated with a “B”. (A bit is abbreviated with a small “b”.) Computer storage is usually measured in byte multiples. For example, an 820 MB hard drive holds a nominal 820 million bytes – or megabytes – of data. Byte multiples are based on powers of 2 and commonly expressed as a “rounded off” decimal number. For example, one megabyte (“one million bytes”) is actually 1,048,576 (decimal) bytes. (Confusingly, however, some hard disk manufacturers and dictionary sources state that bytes for computer storage should be calculated as powers of 10 so that a megabyte really would be one million decimal bytes.)
Abbreviation for binary term, a unit of storage capable of holding a single character. On almost all modern computers, a byte is equal to 8 bits. Large amounts of memory are indicated in terms of kilobytes (1,024 bytes), megabytes (1,048,576 bytes), and gigabytes (1,073,741,824 bytes).
- A special high-speed storage mechanism. Cache can be either a reserved section of main memory or an independent high-speed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching.
A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.
L1 and L2 Caches
Some memory caches are built into the architecture of microprocessors. The Intel 80486 microprocessor, for example, contains an 8K memory cache, and the Pentium has a 16K cache. Such internal caches are often called Level 1 (L1) caches. Most modern PCs also come with external cache memory, called Level 2 (L2) caches. These caches sit between the CPU and the DRAM. Like L1 caches, L2 caches are composed of SRAM but they are much larger.
Disk caching works under the same principle as memory caching, but instead of using high-speed SRAM, a disk cache uses conventional main memory. The most recently accessed data from the disk (as well as adjacent sectors) is stored in a memory buffer. When a program needs to access data from the disk, it first checks the disk cache to see if the data is there. Disk caching can dramatically improve the performance of applications, because accessing a byte of data in RAM can be thousands of times faster than accessing a byte on a hard disk.
When data is found in the cache, it is called a cache hit, and the effectiveness of a cache is judged by its hit rate. Many cache systems use a technique known as smart caching, in which the system can recognize certain types of frequently used data. The strategies for determining which information should be kept in the cache constitute some of the more interesting problems in computer science.
A cache, in computing, is a data storing technique that provides the ability to access data or files at a higher speed.
Caches are implemented both in hardware and software. Caching serves as an intermediary component between the primary storage appliance and the recipient hardware or software device to reduce the latency in data access.
A cache works in both hardware and software to provide similar functionality. In its physical or hardware form, it is a small form factor of internal memory that stores instances of the most frequently executed programs in the main memory to enable faster access when they are requested by the CPU.
- Command line interface (CLI)
- A CLI (command line interface) is a user interface to a computer’s operating system or an application in which the user responds to a visual prompt by typing in a command on a specified line, receives a response back from the system, and then enters another command, and so forth. The MS-DOS Prompt application in a Windows operating system is an example of the provision of a command line interface. Today, most users prefer the graphical user interface (GUI) offered by Windows, Mac OS, BeOS, and others. Typically, most of today’s UNIX-based systems offer both a command line interface and a graphical user interface.
The line on the display screen where a command is expected. Generally, the command line is the line that contains the most recently displayed command prompt .
Short for command line interface, a user interface common to MS-DOS computers. The user sees the command line on the monitor and a promptthat is waiting to accept instructions from the user. The user types in the command, the computer acts on that command and then issues a new prompt for the next instruction from the user.
CLI operating systems are becoming less used as GUI operating systems gain in popularity. In a GUI operating system, such as Windows, the user responds to graphic images on the screen instead of typing in commands in response to a prompt.
- COMPUter SECurity (COMPUSEC)
- COMPUter SECurity (COMPUSEC) is a military term used in reference to the security of computer system information. Today it can relate to either the military or civilian community. COMPUSEC also concerns preventing unauthorized users from gaining entry to a computer system.
The differences between computer security (COMSEC) and COMPUSEC is that COMSEC is involved with data that is being transmitted and protecting the data while being transmitted. COMPUSEC concerns itself with protecting data during the act of processing or while being stored.
In the computer industry, the term security — or the phrase computer security — refers to techniques for ensuring that data stored in a computer cannot be read or compromised by any individuals without authorization. Most computer security measures involve data encryption and passwords. Data encryption is the translation of data into a form that is unintelligible without a deciphering mechanism. A password is a secret word or phrase that gives a user access to a particular program or system.
- CPU (central processing unit)
- CPU (central processing unit) is an older term for processor and microprocessor, the central unit in a computer containing the logic circuitry that performs the instructions of a computer’s programs.
A processor is the logic circuitry that responds to and processes the basic instructions that drive a computer.
The term processor has generally replaced the term central processing unit (CPU). The processor in a personal computer or embedded in small devices is often called a microprocessor.
CPU (pronounced as separate letters) is the abbreviation for central processing unit.
Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is the brains of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.
On large machines, the CPU requires one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. Since the 1970’s the microprocessor class of CPUs has almost completely overtaken all other CPU implementations.
The CPU itself is an internal component of the computer. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard.
Each motherboard will support only a specific type (or range) of CPU, so you must check the motherboard manufacturer’s specifications before attempting to replace or upgrade a CPU in your computer. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat.
Components of a CPU
Two typical components of a CPU are the following:
The arithmetic logic unit (ALU), which performs arithmetic and logical operations.
The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
- Desktop is an IT term for the most fundamental and basic element of a personal computer’s graphical user interface. The desktop display is the default display on the computer when it is booted up; auxiliary features like docks provide end users with options for working from a desktop.
As personal computers evolved from operating systems based on command line to more advanced GUI designs, the desktop remained a common concept in design. Users can change the background image of a desktop, customize icons, or otherwise arrange the desktop into what most appeals to them in terms of aesthetics and function.
New innovations in desktop design include desktop virtualization and desktop-as-a-service, where remote control of the desktop may be part of a provided tech service. This type of remotely provided interface works with cloud services, where more of the computer’s programming and file supply resides in a safe external location.
In graphical user interfaces, a desktop is the metaphor used to portray file systems. Such a desktop consists of pictures, called icons, that show cabinets, files, folders, and various types of documents(that is, letters, reports, pictures). You can arrange the icons on the electronic desktop just as you can arrange real objects on a real desktop — moving them around, putting one on top of another, reshuffling them, and throwing them away.
- An organizational unit, or container, used to organize folders and files into a hierarchical structure. Directories contain bookkeeping information about files that are, figuratively speaking, beneath them in the hierarchy. You can think of a directory as a file cabinet that contains folders that contain files. Many graphical user interfaces use the term folder instead of directory.
Computer manuals often describe directories and file structures in terms of an inverted tree. The files and directories at any level are contained in the directory above them. To access a file, you may need to specify the names of all the directories above it. You do this by specifying a path.
The topmost directory in any file is called the root directory. A directory that is below another directory is called a subdirectory. A directory above a subdirectory is called the parent directory. Under DOS and Windows, the root directory is a back slash (\).
To read information from, or write information into, a directory, you must use an operating system command. You cannot directly edit directory files. For example, the DIR command in DOSreads a directory file and displays its contents.
A directory is, in general, an approach to organizing information, the most familiar example being a telephone directory.
1) On the World Wide Web, a directory is a subject guide, typically organized by major topics and subtopics. The best-known directory is the one at Yahoo (http://www.yahoo.com). Many other sites now use a Yahoo-like directory including major portal sites.
2) In computer file systems, a directory is a named group of related files that are separated by the naming convention from other groups of files.
3) In computer networks, a directory is a collection of users, user passwords, and, usually, information about what network resources they can access.
- DOS (disk operating system)
- Acronym for disk operating system. The term DOS can refer to any operating system, but it is most often used as a shorthand for MS-DOS (Microsoft disk operating system). Originally developed by Microsoft for IBM, MS-DOS was the standard operating system for IBM-compatible personal computers.
The initial versions of DOS were very simple and resembled another operating system called CP/M. Subsequent versions have became increasingly sophisticated as they incorporated features of minicomputer operating systems. However, DOS is still a 16-bit operating system and does not support multiple users or multitasking.
For some time, it has been widely acknowledged that DOS is insufficient for modern computer applications. Microsoft Windows helped alleviate some problems, but still, it sat on top of DOS and relied on DOS for many services. Even Windows 95 sat on top of DOS. Newer operating systems, such as Windows NT and OS/2 Warp, do not rely on DOS to the same extent, although they can execute DOS-based programs. It is expected that as these operating systems gain market share, DOS will eventually disappear. In the meantime, Caldera, Inc. markets a version of DOS called DR-OpenDOSthat extends MS-DOS in significant ways.
DOS (Disk Operating System) was the first widely-installed operating system for personal computers. (Earlier, the same name had been used for an IBM operating system for a line of business computers.)
The first personal computer version of DOS, called PC-DOS, was developed for IBM by Bill Gates and his new Microsoft Corporation. He retained the rights to market a Microsoft version, called MS-DOS. PC-DOS and MS-DOS are almost identical and most users have referred to either of them as just “DOS.” DOS was (and still is) a non-graphical line-oriented command- or menu-driven operating system, with a relatively simple interface but not overly “friendly” user interface. Its prompt to enter a command looks like this:
The first Microsoft Windows operating system was really an application that ran on top of the MS-DOS operating system. Today, Windows operating systems continue to support DOS (or a DOS-like user interface) for special purposes by emulating the operating system.
In the 1970s before the personal computer was invented, IBM had a different and unrelated DOS (Disk Operating System) that ran on smaller business computers. It was replaced by IBM’s VSE operating system.
- A driver is a program that interacts with a particular device or special (frequently optional) kind of software. The driver contains the special knowledge of the device or special software interface that programs using the driver do not. In personal computers, a driver is often packaged as a dynamic link library (DLL) file.
A program that controls a device. Every device, whether it be a printer, disk drive, or keyboard, must have a driver program. Many drivers, such as the keyboard driver, come with the operating system. For other devices, you may need to load a new driver when you connect the device to your computer. In DOS systems, drivers are files with a.SYS extension. In Windows environments, drivers often have a.DRVextension.
A driver acts like a translator between the device and programs that use the device. Each device has its own set of specialized commands that only its driver knows. In contrast, most programs accessdevices by using generic commands. The driver, therefore, accepts generic commands from a program and then translates them into specialized commands for the device.
- Electronic Mail (Email)
- Electronic mail (email) is a digital mechanism for exchanging messages through Internet or intranet communication platforms.
Email messages are relayed through email servers, which are provided by all Internet service providers (ISP).
Emails are transmitted between two dedicated server folders: sender and recipient. A sender saves, sends or forwards email messages, whereas a recipient reads or downloads emails by accessing an email server.
Email messages are comprised of three components, as follows:
Message envelope: Describes the email’s electronic format;
Message header: Includes sender/recipient information and email subject line;
Message body: Includes text, image and file attachments.
Email (or e-mail) is defined as the transmission of messages over communications networks. Typically the messages are notes entered from the keyboard or electronic files stored on disk. Most mainframes, minicomputers, and computer networks have an email system.
Some electronic mail systems are confined to a single computer system or network, but others have gateways to other computer systems, enabling users to send electronic mail anywhere in the world. Companies that are fully computerized make extensive use of e-mail because it is fast, flexible, and reliable.
Typical Components of an Email System
Most e-mail systems include a rudimentary text editor for composing messages, but many allow you to edit your messages using any editor you want. Some systems will also provide basic formatting, including bold, italics, font color and HTML. You can use the program to send the message to a recipient by specifying the recipient’s address. You can also send the same message to several users at once. This is called broadcasting.
Sent messages are stored in electronic mailboxes until the recipient fetches them. To see if you have any mail, you may have to check your electronic mailbox periodically, although many systems alert you when mail is received. After reading your mail, you can store it in a text file, forward it to other users, or delete it. Copies of memos can be printed out on a printer if you want a paper copy.
- Employee monitoring
- Employee monitoring is the use of various methods of workplace surveillance to gather information about the activities and locations of staff members.
Businesses monitor employees to improve productivity and protect corporate resources. The main intention is to prevent unacceptable behavior in the first place and, should that effort fail, to curtail the behavior before it can have a negative effect on the business.
A workplace research study from International Data Corp (IDC) reported that 30-40 percent of employee Internet access time was not work-related. Other statistics: 21-31 percent of employees had sent emails divulging sensitive information, such as intellectual property or trade secrets, outside of the corporate network; 60 percent of all online purchases are made during work hours. In the United States, the annual loss in productivity through onlinegoldbricking is estimated at 40 percent.
Monitoring methods include keystroke logging, wiretapping, GPS tracking and Internet monitoring, which includes surveillance of employees’ web surfing, email, instant messaging and interaction on social networking sites.
Employee monitoring is the act of monitoring employee activity. Organizations engage in employee monitoring to track performance, avoid legal liability, protect trade secrets, and address other security concerns. The practice may impact employee satisfaction due to its impact on privacy.
If employees use company computers for their work, companies often utilize Employee monitoring software that allow them to track everything employees do on their computers. For example, what emails were received, what applications were used and what keys were pressed.
- Ethernet is an array of networking technologies and systems used in local area networks (LAN), where computers are connected within a primary physical space.
Systems using Ethernet communication divide data streams into packets, which are known as frames. Frames include source and destination address information, as well as mechanisms used to detect errors in transmitted data and retransmission requests.
Gigabit Ethernet (GbE) is a form of technology used in Ethernet frame transmissions, where Gb refers to the data transmission rate expressed in units of 1,000,000,000 bps. GbE data is transmitted in bundled units, which ensures delivery of the majority of data, even when there are destination delays with one frame or packet. Thus, not all of the data is held back while transmitting and receiving computers grapple with minor data delays.
Ethernet transmission speeds are constantly improving and evolving. For example, 100BASE-TX and 1000BASE-T reference the physical Ethernet layer, which contains twisted pair cables and 8 Position 8 Contact (8P8C) modular connectors with male plugs and female jacks. These run at 100 Mbps and 1 Gbps, respectively. 100BASE-TX is also known as Fast Ethernet, where more common coaxial cables are replaced by twisted pair cables, enabling faster frame transmissions.
Carrier Ethernet is a high-bandwidth technology used for Internet access and connectivity by government, business and academic LANs.
Ethernet is the most widely installed local area network (LAN) technology. Ethernet is a link layer protocol in the TCP/IP stack, describing how networked devices can format data for transmission to other network devices on the same network segment, and how to put that data out on the network connection. It touches both Layer 1 (the physical layer) and Layer 2 (the data link layer) on the OSI network protocol model. Ethernet defines two units of transmission, packet and frame. The frame includes not just the “payload” of data being transmitted but also addressing information identifying the physical “Media Access Control” (MAC) addresses of both sender and receiver, VLAN tagging and quality of service information, and error-correction information to detect problems in transmission. Each frame is wrapped in a packet, which affixes several bytes of information used in establishing the connection and marking where the frame starts.
Specified in the family of standards known as IEEE 802.3, Ethernet was originally developed by Xerox in the 1970s. Ethernet was initially designed to run over coaxial cables, but a typical Ethernet LAN now uses special grades of twisted pair cables, or fiber optical cabling. Wi-Fi standards (IEEE 802.11a, b, g, n and now ac) define the equivalent of Ethernet for Wireless LANs.) Ethernet standards are steadily evolving to embrace new media, higher transmission speeds and changes in frame content (e.g., 802.3ac to accommodate VLAN and priority tagging) and functional requirements (e.g., 802.3af, defining Power Over Ethernet [POE] crucial to most Wi-Fi and IP telephony deployments).
- FAQ(frequently asked questions)
- Pronounced as separate letters, or as “fak,” and short for frequently asked questions, a FAQ is an online documentthat poses a series of common questions and answers on a specific topic. FAQs originated in Usenet groups as a way to answer questions about the rules of the service. Today, there are FAQs on the Web for many topics, ranging from programming langauges to gardening tips.
Frequently, FAQs are formatted as help files or hypertextdocuments.
The FAQ (pronounced FAK) or list of “frequently-asked questions” (and answers) has become a feature of the Internet. The FAQ seems to have originated in many of the Usenet groups as a way to acquaint new users with the rules. Today, there are thousands of FAQs on the World Wide Web.
To see the range and variety of topics for which FAQs have been written, go to Google or any major search engine, and enter “faq” or “faqs” in the search entry box. To find a FAQ on a subject of interest (for example, hedgehogs), enter “faq and hedgehogs”(without the quotes). Also note that the number of subjects on which you will NOT find a FAQ is also large. The most useful FAQs are often found at a Web site you’ve discovered through other search approaches.
- In data processing, using an office metaphor, a file is a related collection of records. For example, you might put the records you have on each of your customers in a file. In turn, each record would consist of fields for individual data items, such as customer name, customer number, customer address, and so forth. By providing the same information in the same fields in each record (so that all records are consistent), your file will be easily accessible for analysis and manipulation by a computer program. This use of the term has become somewhat less important with the advent of the database and its emphasis on the table as a way of collecting record and field data. In mainframe systems, the term data set is generally synonymous with file but implies a specific form of organization recognized by a particular access method. Depending on the operating system, files (and data sets) are contained within a catalog, directory, or folder.
In any computer system but especially in personal computers, a file is an entity of data available to system users (including the system itself and its application programs) that is capable of being manipulated as an entity (for example, moved from one file directory to another). The file must have a unique name within its own directory. Some operating systems and applications describe files with given formats by giving them a particular file name suffix. (The file name suffix is also known as a file name extension.) For example, a program or executable file is sometimes given or required to have an “.exe” suffix. In general, the suffixes tend to be as descriptive of the formats as they can within the limits of the number of characters allowed for suffixes by the operating system.
A collection of data or information that has a name, called the filename. Almost all information stored in a computer must be in a file. There are many different types of files: data files, text files , program files, directory files, and so on. Different types of files store different types of information. For example, program files store programs, whereas text files store text.
- File Transfer Protocol (FTP)
- File Transfer Protocol (FTP) is a client/server protocol used for transferring files to or exchanging files with a host computer. It may be authenticated with user names and passwords. Anonymous FTP allows users to access files, programs and other data from the Internet without the need for a user ID or password. Web sites are sometimes designed to allow users to use ‘anonymous’ or ‘guest’ as a user ID and an email address for a password. Publicly available flies are often found in a directory called pub and can be easily FTPed to a user’s computer. FTP is also the Internet standard for moving or transferring files from one computer to another using TCP or IP networks.
File Transfer Protocol is also known as RFC 959.
The original FTP specification was written by Abhay Bhushan and published as RFC 114 on April 16, 1971. This was later replaced by RFC 765 (June 1980). The current specification is RFC 959 (October 1985). RFC stands for request for comments.
There are various uses for and types of FTP:
An FTP site is a web site where users can easily upload or download specific files.
FTP by mail allows users without access to the Internet to access and copy files using anonymous FTP by sending an email message to firstname.lastname@example.org and putting the word help in the body of the text.
FTP Explorer is an FTP client based on Windows 95 file manager (Windows 95 Explorer).
An FTP server is a dedicated computer which provides an FTP service. This invites hackers and necessitates security hardware or software such as utilizing usernames, passwords and file access control.
An FTP client is a computer application which accesses an FTP server. While doing so, users should block incoming FTP connection attempts using passive mode and should check for viruses on all downloaded files.
Short for File Transfer Protocol, the protocol for exchanging files over the Internet. FTP works in the same way as HTTP for transferring Web pages from a server to a user’s browser and SMTP for transferring electronic mail across the Internet in that, like these technologies, FTP uses the Internet’s TCP/IP protocols to enable data transfer.
FTP is most commonly used to download a file from a server using the Internet or to upload a file to a server (e.g., uploading a Web page file to a server).
- Hypertext Transfer Protocol (HTTP)
- HyperText Transfer Protocol (HTTP) is an application-layer protocol used primarily on the World Wide Web. HTTP uses a client-server model where the web browser is the client and communicates with the webserver that hosts the website. The browser uses HTTP, which is carried over TCP/IP to communicate to the server and retrieve Web content for the user.
HTTP is a widely used protocol and has been rapidly adopted over the Internet because of its simplicity. It is a stateless and connectionless protocol.
Although HTTP’s simplicity is its greatest strength it is also its main drawback. As a result, the HyperText Transfer Protocol – Next Generation (HTTP-NG) project has emerged as an attempt to replace HTTP. HTTP-NG promises to deliver a much higher performance and additional features to support efficient commercial applications in addition to simplifying HTTP’s security and authentication features. Some of HTTP-NG’s goals have already been implemented in HTTP/1.1, which incorporates performance, security and other feature improvements to its original version HTTP/1.0.
A basic HTTP request involves the following steps:
A connection to the HTTP server is opened.
A request is sent to the server.
Some processing is done by the server.
A response from the server is sent back.
The connection is closed.
HTTP is the underlying protocol used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. For example, when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page.
The other main standard that controls how the World Wide Web works is HTML, which covers how Web pages are formatted and displayed.
- Information Security Policy
- Information security policy is a set of policies issued by an organization to ensure that all information technology users within the domain of the organization or its networks comply with rules and guidelines related to the security of the information stored digitally at any point in the network or within the organization’s boundaries of authority.
The evolution of computer networks has made the sharing of information ever more prevalent. Information is now exchanged at the rate of trillions of bytes per millisecond, daily numbers that might extend beyond comprehension or available nomenclature. A proportion of that data is not intended for sharing beyond a limited group and much data is protected by law or intellectual property. An information security policy endeavors to enact those protections and limit the distribution of data not in the public domain to authorized recipients.
Every organization needs to protect its data and also control how it should be distributed both within and without the organizational boundaries. This may mean that information may have to be encrypted, authorized through a third party or institution and may have restrictions placed on its ditstribution with reference to a classification system laid out in the information security policy.
An example of the use of an information security policy might be in a data storage facility which stores database records on behalf of medical facilities. These records are sensitive and cannot be shared, under penalty of law, with any unauthorized recipient whether a real person or another device. An information security policy would be enabled within the software that the facility uses to manage the data they are responsible for. In addition, workers would generally be contractually bound to comply with such a policy and would have to have sight of it prior to operating the data management software.
A business might employ an information security policy to protect its digital assets and intellectual rights in efforts to prevent theft of industrial secrets and information that could benefit competitors.
A security policy is a document that outlines the rules, laws and practices for computer network access. This document regulates how an organization will manage, protect and distribute its sensitive information (both corporate and client information) and lays the framework for the computer-network-oriented security of the organization.
- Interface is often divided into three categories:
A user interface, consisting of the set of dials, knobs, operating system commands, graphical display formats, and other devices provided by a computer or a program to allow the user to communicate and use the computer or program.
A graphical user interface (GUI) provides its user a more or less “picture-oriented” way to interact with technology. A GUI is usually a more satisfying or user-friendly interface to a computer system.
A programming interface, consisting of the set of statements, functions, options, and other ways of expressing program instructions and data provided by a program or language for a programmer to use.
A boundary across which two independent systems meet and act on or communicate with each other. In computer technology, there are several types of interfaces.
user interface – the keyboard, mouse, menus of a computer system. The user interface allows the user to communicate with the operating system. Also see GUI.
software interface – the languages and codes that the applications use to communicate with each other and with the hardware.
hardware interface – the wires, plugs and sockets that hardware devices use to communicate with each other, to connect with or interact with by means of an interface.
- Internet Security
- Internet security is a catch-all term for a very broad issue covering security for transactions made over the Internet. Generally, Internet security encompasses browser security, the security of data entered through a Web form, and overall authentication and protection of data sent via Internet Protocol.
Internet security relies on specific resources and standards for protecting data that gets sent through the Internet. This includes various kinds of encryption such as Pretty Good Privacy (PGP). Other aspects of a secure Web setup includes firewalls, which block unwanted traffic, and anti-malware, anti-spyware and anti-virus programs that work from specific networks or devices to monitor Internet traffic for dangerous attachments.
Internet security is generally becoming a top priority for both businesses and governments. Good Internet security protects financial details and much more of what is handled by a business or agency’s servers and network hardware. Insufficient Internet security can threaten to collapse an e-commerce business or any other operation where data gets routed over the Web.
- A kernel is the core component of an operating system. Using interprocess communication and system calls, it acts as a bridge between applications and the data processing performed at the hardware level.
When an operating system is loaded into memory, the kernel loads first and remains in memory until the operating system is shut down again. The kernel is responsible for low-level tasks such as disk management, task management and memory management.
A computer kernel interfaces between the three major computer hardware components, providing services between the application/user interface and the CPU, memory and other hardware I/O devices.
The kernel provides and manages computer resources, allowing other programs to run and use these resources. The kernel also sets up memory address space for applications, loads files with application code into memory, sets up the execution stack for programs and branches out to particular locations inside programs for execution.
The kernel is responsible for:
Process management for application execution
Memory management, allocation and I/O
Device management through the use of device drivers
System call control, which is essential for the execution of kernel services.
The kernel is the central module of an operating system (OS). It is the part of the operating system that loads first, and it remains in main memory. Because it stays in memory, it is important for the kernel to be as small as possible while still providing all the essential services required by other parts of the operating system and applications. The the kernel code is usually loaded into a protected area of memory to prevent it from being overwritten by programs or other parts of the operating system.
Typically, the kernel is responsible for memory management, process and task management, and disk management. The kernel connects the system hardware to the application software. Every operating system has a kernel. For example the Linux kernel is used numerous operating systems including Linux, FreeBSD, Android and others.
- On most computers, a keyboard is the primary text input device. (The mouse is also a primary input device but lacks the ability to easily transmit textual information.) The keyboard also contains certain standard function keys, such as the Escape key, tab and cursor movement keys, shift and control keys, and sometimes other manufacturer-customized keys.
The computer keyboard uses the same key arrangement as the mechanical and electronic typewriter keyboards that preceded the computer. The standard arrangement of alphabetic keys is known as the Qwerty (pronounced KWEHR-tee) keyboard, its name deriving from the arrangement of the five keys at the upper left of the three rows of alphabetic keys. This arrangement, invented for one of the earliest mechanical typewriters, dates back to the 1870s. Another well-known key arrangement is the Dvorak (pronounced duh-VOR-ak, not like the Czech composer) system, which was designed to be easier to learn and use. The Dvorak keyboard was designed with the most common consonants on one side of the middle or home row and the vowels on the other side so that typing tends to alternate key strokes back and forth between hands. Although the Dvorak keyboard has never been widely used, it has adherents.
Because many keyboard users develop a cumulative trauma disorder, such as carpal tunnel syndrome, a number of ergonomic keyboards have been developed. Approaches include keyboards contoured to alleviate stress and foot-driven pedals for certain keys or keyboard functions.
A keyboard is the set of typewriter-like keys that enables you to enter data into a computer and other devices. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys. The keys typically found on computer keyboards are often classified as follows:
Alphanumeric keys: The letters and numbers on the keyboard.
Punctuation keys: The comma, period, semicolon, and similiar keys.
Special keys: This includes the function keys, control keys, arrow keys, caps Lock key, and so on.
QWERTY, AZERTY, Dvorak and Other Keyboards
The standard layout of letters, numbers, and punctuation is known as a QWERTY keyboard because the first six keys on the top row of letters spell QWERTY. The QWERTY keyboard was designed in the 1800s for mechanical typewriters and was actually designed to slow typists down to avoid jamming the keys.
- Keystroke Logger
- A keystroke logger is a device or program that allows the user to monitor what another user types into a device. In some cases, a keystroke logger is hardware that attaches to the keyboard or another part of a hardware system. In other cases, it is a program that is considered a type of spyware that can be slipped into a system and used in various ways, many of which are illegal.
A keystroke logger may also be called a keylogger.
In terms of the makeup of a keystroke logger spyware program, its most basic elements often include a dynamic link library (DLL), and an executable that runs the file. As the keystroke logger represents a somewhat common type of spyware or malware, there is a focus on how to identify, isolate and disarm these types of monitoring programs. Some users rely on utilities like tcpview to catch keystroke loggers, while others purchase anti-malware and anti-spyware programs that specialize in identifying these threats.
A keylogger, sometimes called a keystroke logger, key logger, or system monitor, is a hardware device or small program that monitors each keystroke a user types on a specific computer’s keyboard. As a hardware device, a keylogger is a small battery-sized plug that serves as a connector between the user’s keyboard and computer. Because the device resembles an ordinary keyboard plug, it is relatively easy for someone who wants to monitor a user’s behavior to physically hide such a device “in plain sight.” (It also helps that most workstation keyboards plug into the back of the computer.) As the user types, the device collects each keystroke and saves it as text in its own miniature hard drive. At a later point in time, the person who installed the keylogger must return and physically remove the device in order to access the information the device has gathered.
- Using hypertext, a link is a selectable connection from one word, picture, or information object to another. In a multimedia environment such as the World Wide Web, such objects can include sound and motion video sequences. The most common form of link is the highlighted word or picture that can be selected by the user (with a mouse or in some other fashion), resulting in the immediate delivery and view of another file. The highlighted object is referred to as an anchor. The anchor reference and the object referred to constitute a hypertext link.
Although most links do not offer the user a choice of types of link, it would be possible for the user to be provided a choice of link types, such as: a definition of the object, an example of it, a picture of it, a smaller or larger picture of it, and so forth.
Links are what make the World Wide Web a web.
In telecommunications, a link is a physical (and, in some usages, a logical) connection between two points.
(1)In communications, a link is a line or channel over which data is transmitted.
(2) In data management systems, a link is a pointer to another record. You can connect one or more records by inserting links into them.
(3) In some operating systems (UNIX, for example), a link is a pointer to a file. Links make it possible to reference a file by several different names and to access a file without specifying a full path.
(4) In hypertext systems, such as the World Wide Web, a link is a reference to another document. Such links are sometimes called hot links because they take you to other document when you click on them.
- Local Area Network (LAN)
- A local area network (LAN) is a computer network within a small geographical area such as a home, school, computer laboratory, office building or group of buildings.
A LAN is composed of inter-connected workstations and personal computers which are each capable of accessing and sharing data and devices, such as printers, scanners and data storage devices, anywhere on the LAN. LANs are characterized by higher communication and data transfer rates and the lack of any need for leased communication lines.
In the 1960s, large colleges and universities had the first local area networks (LAN). In the mid-1970s, Ethernet was developed by Xerox PARC (Xerox Palo Alto Research Center) and deployed in 1976. Chase Manhattan Bank in New York had the first commercial use of a LAN in December 1977. In the late 1970s and early 1980s, it was common to have tens or hundreds of individual computers located in the same site. Many users and administrators were attracted to the concept of multiple computers sharing expensive disk space and laser printers.
A local-area network (LAN) is a computer network that spans a relatively small area. Most often, a LAN is confined to a single room, building or group of buildings, however, one LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide-area network (WAN).
Most LANs connect workstations and personal computers. Each node (individual computer ) in a LAN has its own CPU with which it executes programs, but it also is able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers, as well as data. Users can also use the LAN to communicate with each other, by sending email or engaging in chat sessions.
LANs are capable of transmitting data at very fast rates, much faster than data can be transmitted over a telephone line; but the distances are limited and there is also a limit on the number of computers that can be attached to a single LAN.
- Log File
- A log file is a file that keeps a registry of events, processes, messages and communication between various communicating software applications and the operating system. Log files are present in executable software, operating systems and programs whereby all the messages and process details are recorded. Every executable file produces a log file where all activities are noted.
The phenomenon of keeping a log is called logging, whereas a record file itself is called a log file. The most commonly used logging standard is syslog, which is short for “system log.” A software framework has its own predefined log file and it does not usually appear in the overall system log or operating system event log. Syslog automatically produces a time-stamped documentation of processes of a system while in execution and running state as defined in Internet Engineering Task Force (IETF) RFC 5424. The log messages in a log file can be recorded and analyzed later, even after the program has been closed.
A file that lists actions that have occurred. For example, Web servers maintain log files listing every request made to the server. With log file analysis tools, it’s possible to get a good idea of where visitors are coming from, how often they return, and how they navigate through a site. Using cookies enables Webmasters to log even more detailed information about how individual users are accessing a site.
- Internal storage areas in the computer. The term memory identifies data storage that comes in the form of chips, and the word storage is used for memory that exists on tapes or disks. Moreover, the term memory is usually used as a shorthand for physical memory, which refers to the actual chips capable of holding data. Some computers also use virtual memory, which expands physical memory onto a hard disk.
Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM. You can think of main memory as an array of boxes, each of which can hold a single byte of information. A computer that has 1 megabyte of memory, therefore, can hold about 1 million bytes (or characters) of information.
There are several different types of memory:
RAM (random-access memory);
ROM (read-only memory);
PROM (programmable read-only memory);
EPROM (erasable programmable read-only memory);
EEPROM (electrically erasable programmable read-only memory).
- Menu bar
- The menu bar is the part of a browser or application window, typically at the top left side, that houses drop-down menus that allow the user to interact with the content or application in various ways.
In Microsoft Word, for example, the “File” menu, for example, provides options to open a file, create a new one, and save or print — among others. The “Edit” menu allows the user to perform such functions as copying and pasting, finding and replacing text.
A horizontal menu that appears on top of a window. Usually, each option in a menu bar is associated with a pull-down menu.
- Monitoring-as-a-Service (MaaS)
- Monitoring-as-a-service (MaaS) is one of many cloud delivery models under anything as a service (XaaS). It is a framework that facilitates the deployment of monitoring functionalities for various other services and applications within the cloud. The most common application for MaaS is online state monitoring, which continuously tracks certain states of applications, networks, systems, instances or any element that may be deployable within the cloud.
MaaS offerings consist of multiple tools and applications meant to monitor a certain aspect of an application, server, system or any other IT component. There is a need for proper data collection, especially of the performance and real-time statistics of IT components, in order to make proper and informed management possible.
The tools being offered by MaaS providers may vary in some ways, but there are very basic monitoring schemes that have become ad hoc standards simply because of their benefits. State monitoring is one of them, and has become the most widely used feature. It is the overall monitoring of a component in relation to a set metric or standard. In state monitoring, a certain aspect of a component is constantly evaluated, and results are usually displayed in real time or periodically updated as a report. For example, the overall timeout requests measured in a period of time might be evaluated to see if this deviates from what’s considered an acceptable value. Administrators can later take action to rectify faults or even respond in real time. State monitoring is very powerful because notifications now come in almost every form, from emails and text messages to various social media alerts like a tweet or a status update on Facebook.
- Monitoring Software
- Monitoring software observes and tracks the operations and activities of users, applications and network services on a computer or enterprise systems. This type of software provides a way to supervise the overall processes that are performed on a computing system, and provides reporting services to the system or network administrator.
Monitoring software is primarily a type of security and surveillance software installed on an individual system or the corporate network. It can be a standalone application, or function as part of firewall software or hardware, anti-virus software, or an information security software suite. Generally, monitoring software records and logs all incoming/outgoing network traffic, user processes and interactions, and application activities. It includes specific rules, signatures, events and preferences, which describe normal and abnormal system states and activities. It also alerts the administrator if it identifies any violation or breach that results in abnormal system behavior, user activity or network flow. Moreover, such software is also used for spying on employees or users’ activities within a corporate network.
Parental control is a type of monitoring software that blocks specific user activities and issues a notification to parents/administrators in case of any violations or breaches.
Software for monitoring the desktop and online activities of employees, family members, roommates or other users of a computer. Sometimes referred to as parental control software, monitoring software can quietly monitor and log PC and online activities or more actively filter content and block offensive websites from being accessed.
It isn’t always easy to distinguish monitoring software from spyware, which is why at least one of the following criteria must be met in order for the installation of monitoring software to be considered legal:
The owner of the software must also be the owner of the computer it is going to be installed on;
The owner of the software must be the parent of a minor child;
The owner of the software must have the consent of all users of the monitored computer.
- A device that controls the movement of the cursor or pointer on a display screen. A mouse is a small object you can roll along a hard, flat surface. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse’s tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction. Mice contain at least one button and sometimes as many as three, which have different functions depending on what program is running. Some newer mice also include a scroll wheelfor scrolling through long documents.
Invented by Douglas Engelbart of Stanford Research Center in 1963, and pioneered by Xerox in the 1970s, the mouse is one of the great breakthroughs in computer ergonomics because it frees the user to a large extent from using the keyboard. In particular, the mouse is important for graphical user interfaces because you can simply point to options and objects and click a mouse button. Such applications are often called point-and-click programs. The mouse is also useful for graphicsprograms that allow you to draw pictures by using the mouse like a pen, pencil, or paintbrush.
A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position. The mouse first became a widely-used computer tool when Apple Computer made it a standard part of the Apple Macintosh. Today, the mouse is an integral part of the graphical user interface (GUI) of any personal computer. The mouse apparently got its name by being about the same size and color as a toy mouse.
A mouse consists of a metal or plastic housing or casing, a ball that sticks out of the bottom of the casing and is rolled on a flat surface, one or more buttons on the top of the casing, and a cable that connects the mouse to the computer. As the ball is moved over the surface in any direction, a sensor sends impulses to the computer that causes a mouse-responsive program to reposition a visible indicator (called a cursor) on the display screen. The positioning is relative to some variable starting place. Viewing the cursor’s present position, the user readjusts the position by moving the mouse.
- Parental control
- Parental control software refers to a wide spectrum of software programs and resources for a wide variety of different devices and technologies. What all of these have in common is that they facilitate the control of one user, typically a parent, over the use and access of another user, typically a child.
One way to distinguish different types of parental control software is by recognizing which kinds of technologies they work with. One basic and early type of parental control software included channel blockers, content filters and other tools for cable television. Other types of parental controls offer control over a child’s activity on the Internet, where it’s possible for children to view a lot of material many parents find objectionable.
Another way to think about parental control software is in terms of the methodology these programs use. Some parental controls work through content filtering, where specific kinds of content are blocked. Others allow for better monitoring, while still other forms of parental control software may act not as filters, but as directors that guide a child’s activity toward specific educational or other goals. All of these kinds of tools help make a child’s use of technology productive and safe.
A special browser or filtering program designed to reject Web sites not suited for children. Such programs may screen pages by word content, site rating or by URL, using an updated database of objectionable sites, or any combination of these techniques. Parental control software also comes with the operating system in Windows and Mac computers.
- Privacy is the ability of an individual or group to seclude themselves, or information about themselves, and thereby express themselves selectively. The boundaries and content of what is considered private differ among cultures and individuals, but share common themes. When something is private to a person, it usually means that something is inherently special or sensitive to them. The domain of privacy partially overlaps security (confidentiality), which can include the concepts of appropriate use, as well as protection of information. Privacy may also take the form of bodily integrity.
The right not to be subjected to unsanctioned invasion of privacy by the government, corporations or individuals is part of many countries’ privacy laws, and in some cases, constitutions. Almost all countries have laws which in some way limit privacy. An example of this would be law concerning taxation, which normally require the sharing of information about personal income or earnings. In some countries individual privacy may conflict with freedom of speech laws and some laws may require public disclosure of information which would be considered private in other countries and cultures.
Freedom from damaging publicity, public scrutiny, secret surveillance, or unauthorized disclosure of one’s personal data or information, as by a government, corporation, or individual: Ordinary citizens have a qualifiedright to privacy.
- In computing, a program is a specific set of ordered operations for a computer to perform. In the modern computer that John von Neumann outlined in 1945, the program contains a one-at-a-time sequence of instructions that the computer follows. Typically, the program is put into a storage area accessible to the computer. The computer gets one instruction and performs it and then gets the next instruction. The storage area or memory can also contain the data that the instruction operates on. (Note that a program is also a special kind of “data” that tells how to operate on “application or user data.”)
An organized list of instructions that, when executed, causes the computerto behave in a predetermined manner. Without programs, computers are useless.
A program is like a recipe. It contains a list of ingredients (called variables) and a list of directions (called statements) that tell the computer what to do with the variables. The variables can represent numeric data, text, or graphical images.
There are many programming languages — C, C++, Pascal, BASIC, FORTRAN, COBOL, and LISP are just a few. These are all high-level languages. One can also write programs in low-level languages called assembly languages, although this is more difficult. Low-level languages are closer to the language used by a computer, while high-level languages are closer to human languages.
- RAM (random access memory)
- RAM (random access memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer’s processor. RAM is much faster to read from and write to than the other kinds of storage in a computer, the hard disk, floppy disk, and CD-ROM. However, the data in RAM stays there only as long as your computer is running. When you turn the computer off, RAM loses its data. When you turn your computer on again, your operating system and other files are once again loaded into RAM, usually from your hard disk.
RAM can be compared to a person’s short-term memory and the hard disk to the long-term memory. The short-term memory focuses on work at hand, but can only keep so many facts in view at one time. If short-term memory fills up, your brain sometimes is able to refresh it from facts stored in long-term memory. A computer also works this way. If RAM fills up, the processor needs to continually go to the hard disk to overlay old data in RAM with new, slowing down the computer’s operation. Unlike the hard disk which can become completely full of data so that it won’t accept any more, RAM never runs out of memory. It keeps operating, but much more slowly than you may want it to.
How Big is RAM?
RAM is small, both in physical size (it’s stored in microchips) and in the amount of data it can hold. It’s much smaller than your hard disk. A typical computer may come with 256 million bytes of RAM and a hard disk that can hold 40 billion bytes. RAM comes in the form of “discrete” (meaning separate) microchips and also in the form of modules that plug into holes in the computer’s motherboard. These holes connect through a bus or set of electrical paths to the processor. The hard drive, on the other hand, stores data on a magnetized surface that looks like a phonograph record.
RAM (pronounced ramm) is an acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Main Types of RAM
There are two main types of RAM:
DRAM (Dynamic Random Access Memory)
SRAM (Static Random Access Memory).
The two types of RAM differ in the technology they use to hold data, with DRAM being the more common type. In terms of speed, SRAM is faster. DRAM needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM.
DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite SRAM being faster, it’s not as commonly used as DRAM because it’s more expensive. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.
- ROM(read-only memory)
- ROM is “built-in” computer memory containing data that normally can only be read, not written to. ROM contains the programming that allows your computer to be “booted up” or regenerated each time you turn it on. Unlike a computer’s random access memory (RAM), the data in ROM is not lost when the computer power is turned off. The ROM is sustained by a small long-life battery in your computer.
If you ever do the hardware setup procedure with your computer, you effectively will be writing to ROM.
Acronym for read-only memory, computer memory on which data has been prerecorded. Once data has been written onto a ROM chip, it cannot be removed and can only be read.
Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. In addition, ROMs are used extensively in calculators and peripheral devices such as laser printers, whose fontsare often stored in ROMs.
- Refers to the act of copying what is currently displayed on a screento a file or printer. If the system is in graphics mode, the screen capture will result in a graphics file containing a bit map of the image. If the system is in text mode, the screen capture will normally load a file with ASCII codes.
A screenshot, screen capture (or screen-cap), screen dump or screengrab is an image taken by a person to record the visible items displayed on the monitor, television, or other visual output device in use. Usually, this is a digital image using the operating system or software running on the computer, but it can also be a capture made by a camera or a device intercepting the video output of the display.
- A user is a collection of settings and information associated with a user. It can be defined as the explicit digital representation of the identity of the user with respect to the operating environment, which could be operating systems, software applications or websites. The user profile helps in associating characteristics with a user and helps in ascertaining the interactive behavior of the user along with preferences.
A user can contain personal data. Most user profiles have a set of parameters which are either mandatory or optional. In some cases, the user profile could have different sections and tabs. In the case of software applications or network-related ones, user profiles are usually monitored and maintained by administrators. In some cases, they are maintained by the users themselves. The user profile enables the personalization of the system and can help in customizing certain features for his/her needs. Preferences and needs of a user can usually be found with the help of a user profile.
User profiles have information for most attributes like system needs, general data, restrictions and application settings. It can help in specifying the terms for certain features in the system such as profile visibility, layout view, color themes, preferred languages, date format and message display format. User profiles can be created, modified and deleted.
Most user profiles have a user description like account details, user details and password-related information. In most cases, the user profile helps in providing additional security to users. Users can create authentication measures with the help of different features in the user profile, like a secret question or password. A user profile can also help in password recovery or creation of a new password for users in most applications.
An individual who uses a computer. This includes expert programmers as well as novices. An end user is any individual who runs an application program.
- In computers, a utility is a small program that provides an addition to the capabilities provided by the operating system. In some usages, a utility is a special and nonessential part of the operating system. The print “utility” that comes with the operating system is an example. It’s not absolutely required to run programs and, if it didn’t come with the operating system, you could perhaps add it. In other usages, a utility is an application that is very specialized and relatively limited in capability. A good example is a search-and-replace utility. Some operating systems provide a limited capability to do a search-and-replace for given character strings. You can add a much more capable search-and-replace utility that runs as an application program. However, compared to a word processor, a search-and-replace utility has limited capability.
A program that performs a very specific task, usually related to managing system resources. Operating systems contain a number of utilities for managing disk drives, printers, and other devices.
Utilities differ from applications mostly in terms of size, complexity and function. For example, word processors, spreadsheet programs, and database applications are considered applications because they are large programs that perform a variety of functions not directly related to managing computerresources.
Utilities are sometimes installed as memory-resident programs. On DOS systems, such utilities are called TSRs.
- Virtual Desktop Infrastructure Monitoring(VDI Monitoring)
- Virtual desktop infrastructure monitoring (VDI monitoring) is the process of reviewing, monitoring and managing the operations of a VDI environment for the purpose of performance management, troubleshooting and/or security. It is used to ensure that virtual desktops perform as expected by monitoring the overall operation of desktop infrastructure.
VDI monitoring is an extensive process that includes a series of different processes and methodologies across both the IT/computational and user side of a virtual desktop environment. The IT/computational layer is further divided into the hardware and software tier. VDI monitoring is typically performed through a virtual machine monitor or a VDI-specific monitoring application, such as virtual desktop manager (VDM), which monitors the operations of VDI components at each tier. This may include tracking user activity, operational status and the security of each virtual desktop at a granular level, as well as the composite infrastructure and resource utilization per desktop instance.
- Website monitoring
- Website monitoring is the process of testing and logging the status and uptime performance of one or more websites. This monitoring tool ensures that websites are accessible for all users and is used by businesses and organizations to ensure that website uptime, functionality and performance are always up to standard.
Website monitoring can be done locally within a data center’s firewall where a website is hosted or globally through multiple test sites. Often, this monitoring tool is provided by the service provider through a Web portal with desktop and mobile versions.
There are two ways to monitor websites:
1) Traditional local monitoring: Focuses on the health of the website on the server and may not reflect the experience of a user. As long as the server is running, it appears on local monitoring that the website is functioning as expected.
2) Global monitoring: Tests and monitors uptime and may even identify issues across the Internet backbone. For example, the website may be accessible from most parts of the globe, but not from a specific region because of DNS issues. Global monitoring may spot this, so that the specific issue can be remedied by updating or fixing the DNS server in question. Because of this, global monitoring is also known as end-user monitoring or end-to-end uptime monitoring, which monitors availability and performance experienced by actual users. Thus, it is ideal for diagnosing individual incidents and tracking the impact of website changes.
Website monitoring is the process of testing and verifying that end-users can interact with a website or web application as expected. Website monitoring is often used by businesses to ensure website uptime, performance, and functionality is as expected.
Website monitoring companies provide organizations the ability to consistently monitor a website, or server function, and observe how it responds. The monitoring is often conducted from several locations around the world to a specific website, or server, in order to detect issues related to general Internet latency, network hop issues, and to pinpoint errors. Monitoring companies generally report on these tests in a variety of reports, charts and graphs. When an error is detected monitoring services send out alerts via email, SMS, phone, SNMP trap, pager that may include diagnostic information, such as a network trace route, code capture of a web page’s HTML file, a screen shot of a webpage, and even a video of a website failing. These diagnostics allow network administrators and webmasters to correct issues faster.
Monitoring gathers extensive data on website performance, such as load times, server response times, page element performance that is often analyzed and used to further optimize website performance.
- The WWW prefix (short for World Wide Web) that precedes URL addresses is an indication that the Web address exists on the vast network of the World Wide Web. Sometimes in a URL the “WWW” is followed by a number, such as “WWW1” or “WWW2.” The number that follows the “WWW” indicates that the data being retrieved by the Web browser is gathering the information from a different Web server than the one that serves the typical “WWW” address.
Web sites, especially dynamic Web sites, that handle large amounts of traffic often need more than one server to accommodate the many requests they receive as one server often cannot handle the multitude of requests. The numbers that follow the “WWW refer to different Web servers, often as elements of a server farm, that all contain the exact same information. The servers are used in coordination with each other for load balancing. An example of this system is www.google.com, which uses multiple servers to handle all its traffic. Sometimes the users physical location determines which server receives the routed requests, and sometimes the different servers are used when one or more of the servers need to be taken offline in order to be updated with current information.
A technical definition of the World Wide Web is: all the resources and users on the Internet that are using the Hypertext Transfer Protocol (HTTP).
A broader definition comes from the organization that Web inventor Tim Berners-Lee helped found, the World Wide Web Consortium (W3C):
“The World Wide Web is the universe of network-accessible information, an embodiment of human knowledge.”