Barton County Community College, Great Bend, KS: ITV, Glossary

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Glossary of Technical Terms

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Address - A name, group of numbers or bits used to identify a specific device. (e.g. server, router, switch, printer, or computer) on a network.

Analog - An analog signal transmits information by modulating a continuous signal, such as a radio wave. (See Digital)

Application - An application is the actual program a user activates to work on the computer. There are many computer programs that fit into the category of application; applications are also referred to as software.

Asynchronous - Not synchronized; that is, not occurring at predetermined or regular intervals. The term asynchronous is usually used to describe communications in which data can be transmitted intermittently rather than in a steady stream. For example, a telephone conversation is asynchronous because both parties can talk whenever they like. If the communication were synchronous, each party would be required to wait a specified interval before speaking. (See also Synchronous as opposing technology)

Audio Conferencing - A conferencing system that employs voice-only communications.

Bandwidth - The amount of the electromagnetic spectrum that a given signal occupies. Usually expressed in kilohertz (thousands of hertz, or Khz) or megahertz (millions of hertz or Mhz).

Baud rate - The speed of data transmission over telephone lines, approximately equal to bits per second. A measure of a modem's speed in terms of the amount of information that the modem can transfer from one computer to another in one second; higher baud rates are better. (See also Modem)

Blog - Short for Web log, a blog is a Web page that serves as a publicly accessible personal journal for an individual. Typically updated daily, blogs often reflect the personality of the author.

Buffer - A temporary storage area, usually in RAM. The purpose of most buffers is to act as a holding area, enabling the computer to manipulate data before transferring it to another 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.

Belch, Burst, Burp - An intermittent asynchronous transmission of a specific amount of data. Contrast with streaming. This intermittent asynchronous transmission can cause video and audio problems and is usualy caused by a slow or non-arriving packet.

Bit - Short for binary digit, the smallest unit of information on a machine. A single bit can hold only one of two values: 0 or 1. More meaningful information is obtained by combining consecutive bits into larger units. For example, a byte is composed of 8 consecutive bits.

Byte - 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).

CAT 5 - Category 5 - type of network cable - A term used for a popular style of network cabling adapted from telephone cable. The insulated wires, twisted around each other in pairs but electrically not contacting each other, help to reduce unwanted signals. This wiring may be shielded or unshielded. Sometimes referred to as twisted-pair.

CD-ROM - compact disc-read only memory. A computer storage medium similar to the audio CD which can hold more than 600 megabytes of read-only digital information.

Channel - In data communications, a one-way path along which signals can be sent between two or more points. In telecommunications, a transmission path between two or more points provided by a common carrier.

Chat - Communication between members of an on-line service using text. The messages are sent between members in real time as in a conversation by typing short statements.

Client - A software application on a computer or terminal that allows the user to extract some service from a network server.

Coaxial Cable - A type of network cable similar to the cable used to transmit cable television signals. Coaxial cable is rated in Ohms; 75 ohm coaxial cable is often used for Ethernet-based networks.

Codec - a device that encodes or decodes a signal. For example, telephone companies use codecs to convert binary signals transmitted on their digital networks to analog signals converted on their analog networks.

Common carrier - A government-regulated private company that furnishes the public with telecommunications services. (e.g. phone companies)

Compressed video - A method for sending video signals using less bandwidth than normal by transmitting only changes in moving frames rather than full motion. The reconstituted image exhibits some motion and, depending on the available bandwidth and capacity of the transmitters and receivers, the motion may appear somewhat irregular. This effect occurs in compressed video technology because the moving areas of the image are only approximated.

Concentrator - Another term for a networking hub. (See also hub)

Connect time - Usually this term refers to the amount of time that a terminal or computer has been logged on to a computer or server for a particular session.

Conventional Memory - The most basic type of memory in a computer used to run programs designed for use with DOS. conventional memory is limited to 640K. (DOS and Windows)

CSU/DSU - Channel Service Unit/Data Service Unit - The CSU is a device that connects a terminal to a digital line. Typically, the two devices are packaged as a single unit. The DSU is a device that performs protective and diagnostic functions for a telecommunications line. You can think of it as a very high-powered and expensive modem. Such a device is required for both ends of a T-1 or T-3 connection, and the units at both ends must be set to the same communications standard.

Dedicated Line - A private line leased from a telecommunications carrier.

Demarcation Point - Also called a point of demarcation (abbreviated POD), the physical point at which the public network of a telecommunications company (i.e., a phone or cable company) ends and the private network of a customer begins.

Digital - Describes any system based on discontinuous data or events. Computers are digital machines because at their most basic level they can distinguish between just two values, 0 and 1, or off and on. There is no simple way to represent all the values in between, such as 0.25. All data that a computer processes must be encoded digitally, as a series of zeroes and ones. (See also Analog)

Domain Name - The identification given to a computer on the Internet or network. Domain names are used to make sure that messages or requests for information are sent to the correct computer on the Internet or network. Domain names have two or more parts separated by periods.

DOS - An acronym for disk operating system. DOS is the main program that coordinates all functions of IBM-compatible PC, from running programs to saving and loading information from disks.

Downlink - The portion of a satellite circuit extending from the satellite to an earth receive station.

Download - The electronic transferring, or copying, of a file from one computer to another. Files may be downloaded from another connected individual computer, from a computer network, a commercial on-line service or from the Internet.

E-Mail - electronic mail - A message that is sent electronically from a computer of one person to the computer of another person.

EGA - enhanced graphics adapter; EGA was the successor to the original GA video standard on IBM and IBM-compatible computers. EGA adapters can display text or graphics in 16 colors on monitors compatible with EGA. EGA adapters are also capable of displaying smaller type (24 lines on any screen), which allows much larger passages of text on any screen.

Enterprise - The entire organization.

Enterprise Network - A geographically-dispersed network under the jurisdiction of one organization. It often includes several different types of networks and computer systems from different vendors.

Ethernet - Ethernet is a particular network topology and protocol, especially useful in LANs. It comes in various speeds and is often regarded as THE current technology for general network direct connection. A long time standard method of connecting computers to a local area network using coaxial cable, invented by Robert Metcalfe at Xerox PARC in the early 1970s. The current connectivity is generally considered to be 10Base-T or 100Base-T, while the backbone, if one is used, is coaxial cable or Fiber optics. There is also a 1000Base-T for certain specialty copper joining situations.

FAQ - Frequently Asked Question

F Connector - A two-wire (signal and ground) coaxial cable connector used to connect antennas, TVs and VCRs. F connector cables typically carry NTSC TV signals (audio and video). The plug's shell and socket are threaded. See picture below.

Fiber Optics - a technology for transmitting voice, video, and data via light over thin fibers of glass. This technology had much greater bandwidth capacity than conventional cable or copper wire.

File - Information, often a document or an application, saved on a disk or other storage medium.

File Compression - Software that makes files smaller than their original size so they take up less space on a disk or other storage medium.

File Server - Computers with large storage devices on a network for storing files and software that can be shared by users on the network.

File Sharing - The ability to share files with other computers on the same network.

Firewall - A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

Firewire - A high-speed serial bus developed by Apple and Texas Instruments that allows for the connection of up to 63 devices. It is widely used for downloading video from digital camcorders to the computer. Also known as the IEEE 1394 standard, the i.Link connector and the High Performance Serial Bus (HPSB), the first version of FireWire supported 100, 200 and 400 Mbits/sec transfer rates and a distance of 4.5 meters between devices. See below for a picture of a firewire connector.

Footprint - The region on earth to which a communications satellite can transmit. Also, the floor or desk surface space taken up by a piece of equipment.

Frequency - Number of cycles per second of an electromagnetic transmission, usually described in hertz.

FTP - file transfer protocol - A standard protocol for sending computer files from one computer to another on the Internet. A method of electronically moving files from one location to another.

Gateway - A device connecting two dissimilar networks that adds security, flow control and protocol conversion. Gateways typically handle protocol conversion operations across a wide spectrum of communications functions or layers, and they require software programming and central management.

GIF - Graphic Interchange Format - a widely used format for image files.

Glitch - A temporary or random hardware malfunction. It is possible that a bug in a program may cause the hardware to appear as if it had a glitch in it and vice versa. At times it can be extremely difficult to determine whether a problem lies within the hardware or the software.

H.323 - A standard approved by the International Telecommunication Union (ITU) that defines how audiovisual conferencing data is transmitted across networks. In theory, H.323 should enable users to participate in the same conference even though they are using different videoconferencing applications.

Hardware - Physical equipment components or devices.

Hertz - A unit of frequency equal to one cycle per second (cps). One kilohertz equals 1,000 cps; one megahertz equals one million cps; one gigahertz equals one billion cps.

Home Page - The first or introductory page that appears when accessing a World Wide web site. The home page often provides the table of contents to a specific website.

HTML - Hypertext Markup Language - The computer language used to design, or write, World Wide Web pages or website's.

HTTP - Hypertext Transfer Protocol - The means or computer protocol by which people using the World Wide Web and Web servers communicate with each other.

Hub - See Switch.

Internet Protocol - IP - A common layer or protocol used on the Internet to connect dissimilar networks and operating systems.

Interoperability - The ability to connect to and exchange data with other hardware and software.

I/O - Input/Output

ISDN - Integrated Services Digital Network. A digital telecommunications technology that provides higher bandwidth and better signal than regular telephone lines.

ITFS - Instructional Television Fixed Service. Line of sight, microwave technology for transmitting and receiving sound and video. Requires Federal Communication Commission licensing and is reserved for educational use.

Jitter - Flickering on a display screen. Jittering can be caused by (a) a number of hardware problems, such as a slow refresh rate, a bad connection between the video adapter and monitor, a hardware malfunction in the monitor, or poor synchronization in the signals being sent; (b) a nearby electrical conduit or transformer creating a higher-than-usual local magnetic field level. Can also be referred to as packet jitter. (Also see Belch)

JPEG - JPG - Short for Joint Photographic Experts Group, and pronounced jay-peg. JPEG is a lossy compression technique for color images. Although it can reduce files sizes to about 5% of their normal size, some detail is lost in the compression.

K - Kilobytes; 1,034 bytes. (See byte)

LAN - Local Area Network - A group of computers and other peripheral devices connected to some type of server for the purpose of sharing resources, such as software applications, files, peripherals and services. A LAN usually refers to a network and can be in one or more rooms and/or a building(s).

Latency - In general, the period of time that one component in a system is spinning its wheels waiting for another component. In networking, the amount of time it takes a packet to travel from source to destination. Together, latency and bandwidth define the speed and capacity of a network.

Laser disk - A plastic disk or platter on which text, video and graphic images can be encoded by means of microscopic pits engraved into the disk; also known as videodiscs. Laser disks are read by special players that transmit a laser beam onto the disks.

LEC - Local Exchange Carrier - (pronounced lex) - An organization that provides local telephone service within the U.S., which includes large companies such as GTE and more than a thousand smaller and rural telephone companies. A LEC provides service from the customer premises to its local exchange (central office) within a local geographic area.
Also known as - LAN Emulation Client - A software driver that provides LAN emulation (LANE) in an ATM network. It resides in an ATM end station or in a computer system that provides the LAN to ATM conversion, often known as a LAN access device

List serve - A software program for combining and automating mailing lists and discussion groups on a computer network or the Internet. A form of one-to-many communication using e-mail.

Local Area Network - see LAN.

Local Loop - In telephony, a local loop refers to the connection between a telecommunication company's central office to the lines in the service subscriber's home or office. Originally, local loop service carried only telephone service to subscribers. But today, with the use of modems, ISDN and DSL signals are transmitted to subscribers as well through the local loop

MCU - Multipoint Conferencing Unit - A device that allows for multiple connections to other conference sites or units.

Modem - Short for modulator-demodulator. A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.

Multipoint - Term used when more than one site is part of a video conference.

NAP - Network Access Port - A public network exchange facility where Internet Service Providers (ISPs) can connect with one another in peering arrangements. The NAPs are a key component of the Internet backbone because the connections within them determine how traffic is routed. They are also the points of most Internet congestion.

NCDLN - North Central Distance Learning Network. NCDLN Website

Netiquette - The rules of conduct for on-line or Internet users.

Network - Two or more computers that are interconnected in some fashion so users can share files and devices (e.g. printers, servers, and storage devices)

Network Switch - See Switch.

Newsgroups - The basic unit of organization on the USENET bulletin board of the Internet. Newsgroups are independent discussions on specific topics.

Node - A termination point for two or more communication links. In local area networks it also refers to a computer or single PC on a network.

Ohm - A unit of measurement for electrical resistance. One ohm is the resistance in a circuit when one volt maintains a current of one amp. The symbol for ohm is the Greek letter omega.

On-line - The state in which a computer is connected to another computer or server via a network. A computer communicating with another computer.

Open - A command that makes a file available so that a user can modify its contents, display it on screen, or send its contents to a printer or other network device for output.

Operating System - OS - The program that organizes and manages the internal activities and functions of the computer or peripheral device.

Packet - A unit of data that is transmitted over a network. It is also commonly used to denote an envelope of data bundled with addressing information for transmission over a network.

Parallel Interface - A port that transmits a number of bits at a time by means of multiple parallel channels. A common parallel interface used in personal computers has 36 channels; eight channels are used to transfer a byte of data at one time, and the other channels are for addressing, error correction, and other control signals.

Parallel Port - The type of port typically used to connect printers to computers. Unlike serial ports, parallel ports send 8 bits of data simultaneously over 8 wires, allowing for a faster relay of information for themselves. (See Serial Port)

PBX - Private Branch Exchange - a private telephone network used within an enterprise. Users of the PBX share a certain number of outside lines for making telephone calls external to the PBX.

PC - Personal Computer, (e.g. desktop computer)

POP - Point of Presence - an access point to the Internet. ISPs have typically multiple POP's. A point of presence is a physical location, either part of the facilities of a telecommunications provider that the ISP rents or a separate location from the telecommunications provider, that houses servers, routers, ATM switches and digital/analog call aggregators.

Protocol - An agreed-upon format for transmitting data between two devices. The protocol determines the following: the type of error checking to be used, data compression method, how the sending device will indicate that it has finished sending a message, how the receiving device will indicate that it has received a message. There are a variety of standard protocols.Each has particular advantages and disadvantages; for example, some are simpler than others, some are more reliable, and some are faster. From a user's point of view, the only interesting aspect about protocols is that your computer or device must support the right ones if you want to communicate with other computers. The protocol can be implemented either in hardware or in software. (See also H.323)

Pull Technology - In reference to the Internet or other on-line services, the technology whereby users utilizing software such as a web browser, are required to locate and "pull down" the information for themselves. (See Push Technology)

Push Technology - In reference to the Internet or other on-line services, the technology whereby information is sent directly to a user's computer. It is similar to e-mail, whereby, when a user logs on to a computer, messages are waiting. Push technology uses sophisticated software and "electronic agents" that operate in the background, search and retrieve information needed by the user and place that information in a mailbox or directory on the user's computer.

Qlink - The control box located at the instructor station in our multi-point ITV classroom by which you switch the various media inputs and outputs for the ITV system. By using the Qlink, you can control many operations instead of using the handheld remote.

RAM - Random Access Memory - RAM is the memory the computer uses to temporarily store information that the microprocessor needs to operate a computer program. The amount of RAM determines the number of programs than can be open on a computer simultaneously. RAM changes as computer programs are opened and closed or the computer is shut down.

RCA Connector - A plug and socket for a two-wire (signal and ground) coaxial cable that is widely used to connect audio and video components. Also called a "phono connector," rows of RCA sockets are found on the backs of stereo amplifiers and numerous A/V products. The prong is 1/8" thick by 5/16" long. See picture below.

Real Time - Communication where information is received at (or nearly at) the instant it is sent.

Receive Site - A location that can receive transmissions from another site for distance learning.

Repeater - A device which amplifies an electrical signal, thereby increasing the transmission distance possible.

ROM - Read-Only Memory - ROM stores special instructions that the computer needs in order to run properly. As the name implies, information stored in ROM is never changes, only read as needed by the computer.

Router - A hardware module and component of a network that receives transmissions and forwards them to intended destinations by the shortest route possible.

RS232 Port - An industry standard port found on modems and some types of printers. RS232 ports usually have 25 pins in two rows on a rectangular socket. RS232 ports are serial ports used to transfer information from a computer to a peripheral device and vice versa.

Save - In computing context, store information by transferring it from main memory (RAM) to a disk or other storage medium or device.

Satellite Dish - Device used for sending or receiving electronic signals from a satellite.

Scanner - A device that converts a printed page or image into an electronic representation that can be viewed and manipulated on a computer. Scanners are often used to convert photographs into electronic representations so that they can be included in documents created on a computer.

Search Engine - An Internet site and software program that allows for keyword searching of on-line information.

Serial Interface - A data channel that transfers digital data in a serial fashion: one bit after the other over one wire or fiber. The serial port on a PC is a serial interface that is typically used to attach modems and data acquisition terminals. On earlier PCs, mice also used the serial port. USB and FireWire (IEEE 1394) are high-speed serial interfaces that have superseded the serial port. Serial interfaces may have multiple lines, but only one line is used for data.

Smart Jack - Synonym for a device that is used to interconnect the Go and Return paths of a circuit at the incoming end, and through which the detection of an incoming check tone transmits another check tone to permit a continuity checking of a 2-wire circuit.

Switch - Network Switch - a device that filters and forwards packets between LAN segments.

Synchronous - Data transmission using synchronization bytes, instead of start/stop bits, to control the transmission. Communication within a computer is usually synchronous and is governed by the microprocessor clock. Signals along the bus, for example, can occur only at specific points in the clock cycle. The opposite of synchronous is asynchronous. (See also Asynchronous)

T1.5 - A 1.544 Mbps point-to-point dedicated, digital circuit provided by the telephone companies. The monthly cost is typically based on distance. T1 lines are widely used for private networks as well as interconnections between an organization's PBX or LAN and the telco.

Technology - The application of knowledge, tools and skills to solve practical problems and extend human capabilities.

Technology Literacy - The ability to use, manage, and understand technology.

Telecommunications - The exchange of voice, video or data through digital or analog electromagnetic or electronic signals (e.g. radio, telephone, television, facsimile, computer/modem).

Teleconference - Communication via audio, video, or computer between two or more groups in separate locations.

TELNET - An application that allows the user to log into a remote, usually UNIX-based computer over the Internet.

Throughput - The rate at which data may be transferred from one computer to another via some sort of electronic medium. Usually measured in bits per second, kilobytes per second or megabytes per second.

Topology - The physical layout of a network. The configuration of links and nodes by which the transmission and technology are interconnected to form a complete system.

Transponder - The equipment on a satellite that receives an electronic signal from a transmitting station, amplifies it, and then retransmits it to receiving stations on earth.

UNIX - An operating system that incorporates the TCP/IP networking protocol. Most servers on the Internet run the UNIX operating system because UNIX is heavily integrated with TCP/IP and because UNIX was optimized to handle requests from multiple network users.

Uplink - The portion of a satellite circuit or a satellite dish which transmits signals from a ground station to the satellite.

Upload - To send a file to another computer or server.

URL - Uniform Resource locater - The address and method used to locate a specific resource or single document on the World Wide Web or Internet.

USB - (Universal Serial Bus) A widely used hardware interface for attaching peripheral devices. USB ports began to appear on PCs in 1997, and Windows 98 was the first Windows to support it natively. Within a few years, USB became popular for connecting nearly every external peripheral device. Replacing the serial and parallel ports on a PC, at least four USB ports are standard on every computer. See below for picture of USB connectors.

USENET - A one-to-many communication system on the Internet that is also available on some smaller networks as well (like FIDONet, which is found in many developing countries). USENET is an informal news and information transfer system that allows users to exchange messages on a bulletin board-like system. (See also LISTSERV)

User Interface - The system of computer screen images, devices, and software components that allow the user to interact with and control the computer's operating system. Graphical User Interfaces (GUI) allow the user to interact with the operating system by manipulating icons or menus. Command-Line interfaces allow users to interact with operating systems by entering commands from the keyboard.

VCR - Abbreviation for videocassette recorder, a device used to record and play video programs.

Workstation - A device, often a microcomputer that serves as an interface between a user and a file server or host computer; a computer or computer terminal.

World Wide Web (WWW) - A spiderweb-like interconnection of millions of pieces of information and documents located on computers around the world. Web documents use a hypertext programming language which incorporates text, sound and graphical images and "links" to other documents and files on interconnected computers. The WWW allows for "point-and-click" navigation of the Internet. Using WWW, it is also possible to search databases and answer on-line surveys.

XVGA - Extended VGA; XVGA is the current successor to SVGA technology. XVGA can display 256 colors in normal mode; some applications can display thousands of colors.

Note: Some technology definitions used on this page were provided with permissions from the following web sites;

Webopedia Online Computer Dictionary for Computer and Internet Terms
Copyright 2004 Jupitermedia Corporation All Rights Reserved.
http://www.webopedia.com

Other Useful Links for Technology Definitions;

San Diego State University Glossary of Academic Information Technology

Computer User High Tech Dictionary

Tech Dictionary