This is a useful glossary of terms for those interested in the Internet and distance education.

Address- The identification of a physical or virtual distinct entity in a network. On the Internet, this network address is known as a URL, Uniform Resource Locator, e.g., http://www.gsh.org.

Analog- A data signal transmitted via radio wave using changes in sine wave. Requires a modem at each end for use with data communications. Most standard telephone lines in the world are analog.

Amplitude- The amount of variety in a signal. Commonly thought of as the height of a wave.

(ARPANET) Advanced Research Projects Agency Network- The first "Internet". Linked UCLA, Stanford and defense contractors beginning in the late 1960's. Retired in 1990 and its younger brother, the Internet, was brought on-line.

(ASCII) American Standard Code for Information Interchange - A standard for digital representation of letters, numbers, and control codes; understood by most computers.

Asynchronous Distance Education- Education in which interaction between instructor and student does not take place simultaneously, e.g., traditional correspondence courses.

Asynchronous Transmission Mode (ATM)- A multiplexed information transfer technique of sending data in irregular time intervals using a code such as ASCII. ATM allows most modern computers to communicate with one another easily.

Backbone- also see MBONE. The primary communication path connecting networks together.

Band- A range of frequencies between defined upper and lower limits.

Bandwidth- Information carrying capacity of a communication channel.

Bit- An acronym for BInary digiT. It is the basic unit of information in the machine world. A bit is a digit in binary form and carries one of two values, 0 or 1.

bps- Bits per second- a measurement of data transmission speed.

Broadband- A loose term used to describe a high bandwidth lines, usually a T-3 line, with 45Mps or higher

Byte- A single computer character, generally eight bits. For example, the letter "G" in binary code is 01000111.

Browser- Software that allows you to find and see information on the Internet.

(CGI) Common Gateway Interface- An interface between a Web site and a user. It allows forms, surveys and other documents to be filled on-line and the results automatically sent to the web site's UNIX server.

Codec (COder/DECoder)- Device used to convert analog signals to digital signals for transmission and reconvert signals upon reception at the remote site while allowing for the signal to be compressed for less expensive transmission.

Compressed Video- Video signals are downsized to allow travel along a smaller carrier.

Compression- Reducing the amount of visual information sent in a signal by only transmitting changes in action.

COM port- Communication or serial port on PCs usually used for a data communication interface

Computer Assisted Instruction (CAI)- Teaching process in which a computer is used to enhance the education of a student.

(CPU) Central Processing Unit - The component of a computer in which data processing takes place.

(CSU/DSU) Customer Service Unit/Digital Service Unit- Sometimes called a digital modem. It does not modulate or demodulate, but converts a computer's uni-polar digital signal to a bi-polar digital signal for transmission over ISDN lines.

Cyberspace- The nebulous "place" where humans interact over computer networks, same as virtual space.

Dial-Up Network- Connection to a network (Internet) using a modem and telephone lines. Usually done with a commercial on-line service, e.g.,AOL, or a Internet Service Provider (ISP) e.g., NETCOM.

Digital- A data signal transmitted using discrete steps in voltage rather than frequency, as in an analog signal.

Distance Education- Conveying knowledge from a distance, see Module One.

Distance Learning- The desired product of Distance Education.

Download- Transfer files from a server to a PC across a network (Internet).

(DVI) Digital Video Interactive - A format for recording digital video onto compact disc allowing for compression and full motion video.

(DVTC) Desktop Videoconferencing- Videoconferencing on a personal computer.

Echo Cancellation- The process of eliminating the acoustic echo in a videoconferencing room.

Electronic Mail (E-mail)- Electronic messages send from one computer user to another.

Facsimile (FAX)- System used to transmit textual or graphical images over standard telephone lines.

FAQ- Frequently Asked Questions.

FDDI Fiber Distributed Data Interface- a standard that defines high-speed fiber networks.

Fiber Optic Cable- Glass fiber that is used for laser transmission of digital signals.

File Transfer Protocol (FTP)- An application program that uses TCP/IP protocol to allow you to move files from a distant computer to a local computer using a network like the Internet.

Frequency- The number of complete oscillations per second of an electromagnetic wave..

Full Duplex- Process that allows both parties to Receive (listen) and transmit (talk) at the same time.

Full Motion Video- Signal which allows transmission of complete action taking place at the origination site.

Fully Interactive Video- (Two way interactive video) Two sites interact with audio and video as if they were collocated.

Half Duplex- Communication process that allows only one parties to transmit (talk) at a time.

Home Page or Homepage- the top level hypertext document in a collection of pages or web site. Often uses index.htm as file name.

Host- A network computer that can receive information from other computers.

(HTML) HyperText Markup Language- The programming language used to create web pages.

(HTTP) Hypertext Transfer Protocol - The protocol used to provide hyper text links between pages.

Hypertext- A document which has been marked up to allow a user to select words or pictures within the document, click on them, and connect to further information.

Instructional Television Fixed Service (ITFS)- Microwave-based, high-frequency television used in educational program delivery.

Integrated Services Digital Network (ISDN)- A digital telecommunications standard allowing communication channels to carry voice, video, and data simultaneously, see module three.

Interactive Media- Frequency assignment that allows for a two-way interaction or exchange of information.

Internet- A worldwide network of networks.

(IP) Internet Protocol- The underlying packet standard used to connect networks over the Internet. IP is half of a protocol suite that works and must work with TCP.

(ISP) Internet Service Provider- Commercial company that provides access to the Internet. Service is most often provided through a dial-up network.

Kbps- One Thousand bps, actual number is 1024 bps.

Listserv- An e-mail program that allows multiple computer users to connect onto a single system, creating an on-line discussion.

Local Area Network (LAN)- Two or more local computers that are physically connected.

(MBONE) Multicast Backbone- a network that works in conjunction with the Internet for audio and video applications

Microwave- Electromagnetic waves that travel in a straight line and are used to and from satellites and for short distances (i.e., up to 30 miles).

Modem- Acronym for MOulate DEModulate. Hardware that allows computers to interact with each other via telephone lines by converting digital signals to analog for transmission along analog lines.

MOO- Acronym for a lot of things, on of which is Multi-user-dimension Object Oriented. They are multimedia, interactive environments in virtual space. Formerly in the confines of Telnet, MOOs now have taken advantage of the WWW.

Mosaic- A dated example of browser.

Mbps- One million bps, actual number is1,048,576

Multimedia- Any document which uses multiple forms of communication, such as text, audio, and/or video.

Multi-Point Control Unit (MCU)- Computerized switching system which allows point-to-multipoint videoconferencing.

(MPEG) Motion Picture Experts group- video compression standard.

Network- A series of points connected by physical or virtual connects.

On-line- Buzz word that indicates access to a computer network.

(POP) Point of Presence - actual site of an ISP or other service

(PPP) Point-to-Point Protocol- a type of Internet protocol that uses the serial (COM) port connection.

Protocol- A formal set of standards, rules, or formats for exchanging data that assures uniformity between computers and applications.

Satellite TV- Video and audio signals are relayed via a communication device that orbits around the earth.

(SLIP) Serial Line Internet Protocol- Predecessor of PPP. Allows a user to connect to the Internet directly over a high-speed modem.

Server- A computer with a special service function on a network, generally receiving and connecting incoming information traffic.

Synchronous Distance Education- Distance Education that takes place real time but in different locations, the virtual classroom.

T-1 (DS-1)- High speed line capable of carrying 1.54 Mbps. T-1 has 24 voice circuits and can be divided into 12 ISDN lines

T-2 (DS-2)- High speed line capable of carrying 6.312 Mbps. 96 voice circuits

T-3 (DS-3)- High speed line capable of carrying 44.736 Mbps. 672 voice circuits

T-4 (DS-4)- High speed line capable of carrying 274.176 Mbps. 4032 voice circuits

(TCP) Transmission Control Protocol - A protocol which makes sure that packets of data are shipped and received in the intended order. Used with IP.

Telecommunication- The science of information transport using wire, radio, optical, or electromagnetic channels to transmit receive signals for voice or data communications using electrical means.

Uniform Resource Locator (URL)- The address of http internet sites.

Uplink- The communication link from the transmitting earth station to the satellite.

(WWW) World Wide Web- A network of graphical hypertext servers linked by the Internet.

Glossary courtesy of Virtual University.