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Cable modems are special modems that connect to the cable television outlet. A cable modem provides a broadband connection to the Internet with similar speeds to DSL that uses telephone lines.
Caches are computer system directories or files that store information temporarily to be used later or will be dumped. Some utility software uses special cache files to store temporary information related to its processes. A temporary cache can usually be safely emptied of files when it is not used to free up space on a hard drive.
Caps Lock key refers to a key on the keyboard that is used to lock the keys so that they type all capital letters. It is usually on the left side of the keyboard under the Tab key. When the capitals are locked on there is an LED light on the keyboard that lights up. To turn off the locked capitals key the Caps Lock key is pressed a second time.
Capture refers to the process of digitizing something for use on a computer. For instance, an image can be captured by a camera, a video captured by a video camera, audio captured by a sound card or art captured by a scanner. Anything in a digital form can be manipulated by the computer.
Case sensitive is a descriptive property of being aware of the capitalization of characters. On certain operating system command lines, in some programming languages and scripting languages, and in processes like searches the property of being case sensitive can be important because the user must put in the correct letter either upper or lower case. Most web searches are not case sensitive. The UNIX computer file systems are case sensitive.
Cases for computers are the metal or plastic container where the main computer hardware components are stored. The case protects the interior hardware components and CPU from physical damage.
Catenets are specific type of connected networks in which host systems with varying characteristics are attached to the network, and the networks are interconnected by gateway routers. The Internet is an example of the largest possible catenet.
CATV stands for Community Antenna Television. CATV cable can be used by broadband networks and broadcast TV distributions.
CCITT stands for Consultative Committee for International Telegraphy and Telephony which is a unit of the International Telecommunications Union of the United Nations. This telecommunications consultant organization produces technical standards for some of the internationally controlled side of analog and digital communications.
CCR stands for Commitment, Concurrency, and Recovery. An element used in OSI applications to create atomic operations across distributed computer systems to implement for transactions and nonstop operations.
CD stands for Compact Disc. A CD disc is a removable optical storage media for computers. A CD can either have data on it and be read by the computer, or be a recordable disc. If it is recordable it may be a blank CD-R disc or a CD-RW disc. A computer with a standard CD drive or DVD drive can read a CD when there is data on the disc. A CD burner can be used to imprint data on to a blank CD-R or CD-RW disc using laser optics. The storage capacity on a DVD disc holds many times the capacity of a CD disc. The capacity of a CD is around 700 to 800 megabytes.
CD burners are hardware devices that are a type of CD drives that use optical technology to read and also write information to CD-R or CD-RW discs. They are located inside the computer case facing the front of the system physically attached by an IDE cable to the motherboard. The drives have removable storage trays for insertion of the CD. When the user closes the tray the drive reads the media with laser optics. CD burners are the same thing as CD writers.
CD drives are hardware devices that use optical technology to read information from CD-R discs. They are typically ROM drives that use read only memory, so they cannot write to the disc. They are located inside the computer case facing the front of the system physically attached by an IDE cable to the motherboard. The drives have accessible storage trays for insertion of the compact disc. When the user closes the tray the drive reads the media with laser optics. CD drives can only read a CD-R disc when there is data on it. CD drives are the same thing as CD-ROM drives.
CD writers are hardware devices that are a type of CD drives that use optical technology to read and also write information to CD-R or CD-RW discs. They are located inside the computer case facing the front of the system physically attached by an IDE cable to the motherboard. The drives have removable storage trays for insertion of the CD. When the user closes the tray the drive reads the media with laser optics. CD writers are the same thing as CD burners.
CD-R disc stands for Compact Disc - Recordable disc. A CD recordable disc may have data written on it or may be a blank. A computer with a standard CD drive or DVD drive can read a CD-R disc when there is data it. A CD burner can be used to imprint data on to a blank CD-R disc using optical technologies. Data written to a CD-R disc this way may only be written once. After it is written to the disc it can be read repeatedly.
CD-ROM drives stands for Compact Disc - Read Only Memory drive. They are hardware devices that use optical technology to read information from CD-R discs. ROM drives use read only memory, so they cannot write to the disc. They are located inside the computer case facing the front of the system physically attached by an IDE cable to the motherboard. The drives have accessible storage trays for insertion of the compact disc. When the user closes the tray the drive reads the media with laser optics. CD-ROM drives can only read a CD-R disc when there is data on it. CD-ROM drives are the same thing as CD drives.
CD-RW disc stands for Compact Disc - Rewritable. This CD is a rerecordable disc that can be written to recursively. It can be used with a compatible CD burner that applies optical technologies that allows the user to write, read or delete files. The data can be written to the same CD-RW disc over again and again like a regular hard drive with the benefit of removability.
CDMA stands for Code Division Multiple Access. This protocol for wireless data and voice communication used in cell phone networks also works in other data communications systems. CDMA uses multiple radio frequencies to transmit data to efficiently use the available radio spectrum.
CERN stands for Conseil Europeen pour la Recherche Nucleaire, the European Laboratory for Particle Physics. They conduct high energy physics research and are located in Geneva, Switzerland.
Certificate is the term for a type of digital data files used by the SSL protocol to help establish a secure connection by verifying the remote computer system being used. The certificate verifies that a certificate authority has issued a security certificate to authorize Internet communications. They are usually used with email, web applications and web sites.
Certificate authority refers to the official issuer of a security certificate used in SSL and other secure network connections. This can be a trusted third party who works as a facilitator of certification.
Certification can refer to a product or a system, or even a person. Internet and network communications use certification for securely verifying remote computer systems. They are usually used with email, web applications and web sites. Certification of a system is usually achieved through certificates from certificate authorities.
CGI stands for Common Gateway Interface. This is the environment that exists between users of the web and the web server. CGI is comparable to the API for applications in that it defines the objects available for programmers and developers who create web sites.
Characters are the symbols on the keyboard or on the screen. Characters include the alphanumeric characters as well as special characters. On a keyboard a character can be represented by a standard code such as the common ASCII code.
Chat rooms are web applications where web users can correspond directly to each other in real time through a web site. This allows users with the same interests to communicate directly on the web. It is usually based on the IRC protocol, but also can be created using other protocols.
Checksums are cryptographic values that contain digital fingerprint for a file. They are used to detect any changes made to the data in a packet by simply providing a numerical sum of the data that needs to be checked.
Chips are miniaturized circuits made of silicon used in computers for processing or data storage.
Circuit boards are flat plastic boards with electronic circuits and components soldered on them. The motherboard in a computer is the main circuit board that houses the RAM memory, expansion slots and processing chips. Circuit boards that are used in computers include the cards that fit in the expansion slots such as video cards, NIC cards, sound cards, etc.
Clicking refers to pressing and releasing of the dominant mouse button. The dominant button would usually be the left button when configured for right-handers.
Client refers to any computer system, process or application that is running client-side on a client-server network model.
Client applications are programs on the local computer that connects to another corresponding service on the server computer system in a client-server network relationship. Client applications include web browsers, Telnet, SSH shells and FTP. For instance, the web browser is the client application that views web sites off a corresponding web site server service. The system running a client application that is connected to a server is considered to be the client computer system. A process or application is said to be client-side if it resides on the client.
Client computers are the local computer on a network that may be connected to a server computer system in a client-server relationship. For instance, when accessing the web the web browser is the client application on the client computer that views web sites off a corresponding web server. Other popular client applications that can be on client computers include Telnet, SSH shells and FTP.
Client-server refers to a network architecture model that establishes a special relationship between computers. This relationship describes a network where at least one computer system is predominately supplying server-side services as a server computer. The client computers use client applications to access the service and the servers host the server applications that provides the service. The web is a client-server model, with servers acting as web hosts supplying a service to the client web browsers.
Client-side refers to processes or applications that are run on the client end of a client-server network model. The computer system that is accessing the service is the client computer.
Clipboard is the name of an area used for temporary storage for an operating system. The clipboard stores files and objects when they are cut or copied, before they are pasted.
CLNP stands for Connectionless Network Protocol. This datagram service is an OSI protocol for the OSI Connectionless Network Service. CLNP is the OSI comparable equivalent to the IP for the Internet. CLNP is used in conjunction with CLTP.
Closing in computer terms normally refers to shutting down a file that is open within a software application. If the file has not been saved the application may ask the user to save the file. Closing can terminate all processes and services connected with that application. Occasionally the term close is used to refer to shutting off the entire application. Exit or quit is a more proper term for terminating an application.
CLTP stands for Connectionless Transport Protocol. This protocol provides end-to-end transport, data addressing and checksum error control with no guarantee delivery or flow control. It is basically the OSI equivalent of UDP. CLTP is used in conjunction with CLNP.
CMIP stands for Common Management Information Protocol. It is the OSI network management protocol.
CMOT stands for CMIP Over TCP. It uses the OSI network management protocol CMIP to manage TCP/IP networks over the network.
Co-location usually refers to a server located on a network connected to the Internet that is in another physical location. This can be done to allow the server to get a high-speed Internet connection from another location and also mitigate the security risks of having a connected server on the local area network.
Code refers to the software encoding that is used in programming. Hacking code is a phrase that describes a software programmer writing code using a computer programming language. This is where the term hacker first came from.
Cold boot refers to the booting of a computer system that has been turned off completely. In a cold boot the computer has been turned off at least for a few seconds and so is cold before turning it back on. When a system reboots that is already running it immediately boots back up after shutting down so it is still warm when it restarts which is called a warm boot.
Collisions are when two packets of data on a network overlap and the information being sent becomes unreadable.
Command refers to an instruction to a computer system to do something specific. A command can be delivered through the command line, which is the most basic input interface to a computer. A series of commands can be run from a batch file.
Command line refers to a text based command input to a computer. The command line usually includes a prompt to the user that is accompanied by a flashing cursor on the screen. The user inputs text using the keyboard and then hits the enter key to enter the command. The command line is still a powerful tool in most operating system like UNIX. The two contrasting user interfaces to a computer system are the command line interface and the GUI interface.
Command prompts are the very basic input interface to a computer for the user. The command prompt is a set of designated characters that is accompanied by a flashing cursor on the screen. When the user inputs text using the keyboard it will appear after the command prompt on the screen. Command prompts were originally the only available input to the first computer operating systems. Most all GUI computers still have access to command prompts.
Compiling software refers to getting it ready for execution by converting it to binary code and into an executable file that can be then executed by a user.
Compressed files are computer files that have been compacted to a smaller size, to reduce the amount of storage space they take up. Files can be compressed with or without data loss. Compression done to archive files like ZIP files have no data loss.
Compression is the act of reducing the amount of information stored by extracting data out of a file. Music, photo and video files are good candidates for compression because they can take up a lot of hard drive space. Compressed files can take up a lot less space. For instance JPG files are compressed image files. Compressed files can come with or without data loss. Compression done to JPG files allows the user to adjust the data loss.
Computer refers to the system of devices that combine hardware with software to process data. The basic hardware components of a computer system includes the monitor, keyboard, mouse, along with the interior components located inside the computer case. These include the CPU, the power supply, all drives and the motherboard which houses the main chips, the RAM memory and the expansion cards. All peripheral devices are considered to be computer system hardware too. The basic software for computer systems includes BIOS, operating systems, utilities and software applications.
Computer chips are miniaturized circuits made of silicon used in computers for processing or data storage.
Computer programs are computer software applications. They are sometimes called programs because it is constructed with programming. All software applications need an executable file to start them.
Computer systems are systems of devices that combine hardware with software to process data. The basic components of a computer system includes the monitor, keyboard, mouse and the CPU. The central processing unit which is located inside the computer case includes the motherboard that houses the chips, RAM memory and expansion slots. All internal hardware, expansion cards and peripheral devices are considered to be part of the computer system. The basic software for a computer system includes BIOS, boot loaders, operating systems, utilities and software applications.
Conforming user agents are a certain category of user agent that observes the mandatory web standards set forth by the World Wide Web Consortium. A user agent can be conforming or nonconforming dependent upon if it meets the conditions of those standards. The most common user agent is the web browser. It is both a client application and a web application. Some web browser makers create nonconforming browsers with their own proprietary elements that may or may not be supported by other web browsers. Most web browsers are conforming and support all the HTML elements and HTML attributes as specified by the standards.
Connection-oriented refers to the model of interconnection in which the communication connection occurs in three well-defined phases, establishment, data transfer and release.
Connectionless refer to interconnection between computer systems in which network communications occurs without first establishing any hard wired connection.
Control keys refer to two keys on the keyboard. They are usually located on both bottom corners of each keyboard. They have the letters CTRL or the word Control on them. They can be used in conjunction with other keys. This procedure involves holding down the control key and then pressing the supplemental key. For instance, the directional keys plus the control key can be used in most word processing and text editing programs to quickly jump through text. The Ctrl + right arrow key usually jumps the cursor one word at a time, Ctrl + Home key places the cursor at the beginning of a document and Ctrl + End key places the cursor at the very end of a document. The Ctrl + the C key copies anything selected, the Ctrl + the X key cuts anything selected and the Ctrl + the V key pastes anything from the temporary memory or clipboard.
Control-alt-delete is a special key combination activated by simultaneously holding down the control key and the Alt key and then pressing the delete key once. This combination should be used with caution as it is designed to reset some computer systems. Most systems today will respond first by prompting the user or bring up a task manager showing the user what tasks may be frozen or malfunctioning. This combination of keys can be used with discretion to reboot a system when it is completely frozen.
Control-alt-backspace is a special key combination activated by simultaneously holding down the Control key and the Alt key and then pressing the backspace key once. It is similar to Control-alt-delete on other computer systems. This combination should be used with caution as it is designed to reset some computer systems. This combination can be used with discretion to reboot or log out a system when it is completely frozen.
Controller cards are internal adapters that connect hard disks to the motherboard within a computer. They are generally rare in modern personal computers.
Consoles usually refer to display terminals or to nodes on a network. These nodes would consist of just a monitor, mouse and keyboard. Sometimes consoles can refer to the monitors for computer systems.
Cookies are text files sent from a web site stored on to the client computer. They are tracking files that are downloaded by the web server to try maintain information about the user activities or the computer system through the web browser. When the browser accesses the web site again the site can retrieve the information on the cookie. Cookies can be used to maintain state with the client, to maintain account information or to track items in a shopping cart. Configuration settings on web browsers or on the system firewalls can be set to reject specific cookies or all cookies, although some web sites may not function properly without cookies being accepted.
Copying in computer terms refers to the act of taking a file or an object within a file and preserving a copy of it in a temporary storage area. This area is called the clipboard by some operating systems. Through pasting the item can be retrieved. It stays there until another item replaces it. Copy is part of the three common editing tools, copy, cut and paste.
Core gateways are a set of gateway routers operated by the Internet Network Operations Center. The core gateway network forms a central part of Internet routing and all groups must advertise paths to their networks from a core gateway through a backbone connection using Exterior Gateway Protocol.
COS stands for Corporation for Open Systems. They are a vendor company and user group working for conformance testing, product inspection and promotion of the OSI.
COSINE stands for Cooperation for Open Systems Interconnection Networking in Europe. A program sponsored by the European Commission, aimed at using OSI to tie together European research networks.
CPU stands for Central Processing Unit. This usually refers to the processing and control center for the computer located on the motherboard, including the main processor and other chips used in processing. The CPU can also refer to the computer case and everything inside.
Crackers are individuals that use network tools to crack into other computer system for malicious intent which is not the case of a hacker.
Crash refers to a computer that has stopped working. There are three main types of crashes that can happen to a computer system. Type one is a computer freeze where everything on the screen stops interacting with the user. The control-alt-delete key combination can be used to fix some freezes. Type two is where the system tells the user to shut it off or reboot. For instance, a blue screen might come on and tell the user to reset the system. The third type is where the system either shuts down or reboots by itself. If the last two cases reoccur regularly the operating system might need to be reloaded or the hardware might need to be examined.
CRC stands for Cyclical Redundancy Check. This is the portion of data frames that help for data transmission errors in network communications.
CREN stands for the Corporation for Research and Educational Networking. They control the now merged BITNET and CSNET networks.
CRT stands for Cathode Ray Tube. It is a type of computer monitor that uses an electron cathode ray gun to illuminate the screen by sweeping it repeatedly.
CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection. The access method used to control traffic problems using local area networking technologies such as Ethernet.
CSNET stands for Computer Science NETwork. A large computer network tying together universities, research labs and some commercial companies in the locally and internationally. CSNET recently merged with BITNET to form Corporation for Research and Educational Networking.
CSS stands for Cascading Style Sheets. Style sheets are a method for advanced web page design beyond HTML by expanding a webmasters ability to present a more precise layout. CSS and XML enhanced ways to make web sites and they are supported by all new web browsers.
Cursors are the place on the screen that the computer system designates that input from the keyboard will appear when the user types. The cursor shape can change from application to application, although it is usually shown as a blinking line.
Cutting in computer terms refers to the act of taking a file or an object within a file deleting it, but preserving a copy of it in a temporary storage area. This area is sometimes called a clipboard. Through pasting the item can be retrieved. A copy of it stays there until another item replaces it. Cut is part of the three ubiquitous editing tools, copy, cut and paste.
Cyberspace is a term coined by author William Gibson in his novel Neuromancer. The word cyberspace is currently used to describe the universe of the Internet that consists of the whole range of resources available through computer networks. The root cyber refers to information technology.
