The EdWeb Dictionary

WITHIN THE DICTIONARY are two useful linking functions. First, if you click onto a word that is being defined, EdWeb will connect you to the page where it is primarily mentioned within the actual EdWeb text. Second, If you click onto highlighted words that are referred to within a definition, you will be linked to the definition of that word.

Note: If you can't find a certain word in the EdWeb dictionary, email me at acarvin@gsn.org and I'll cerainly consider adding it.

ADSL

Asymmetric Digital Subscriber Line. A protocol for highspeed digital network access.

ARPAnet

One of the first computer networks, created by the Department of Defense's Advance Research Projects Agency in the 1970's. Eventually evolved into the Internet. No longer in existence.

ASCII

The American Standard Code for Information Interexchange. A protocol which assigns an eight bit code to every letter, number and symbol on a keyboard to allow for universal transmission of basic data. Commonly referred to as "plain text."

ATM

Asynchronous Transfer Mode. Another protocol for sending packets of data at very high speeds. Still in its infancy. Not relation to Automatic Teller Machines.

Backbone

A term used to describe any large channel that interconnects multiple networks.

Bandwidth

The size of a piece of the spectrum (or, the size of a transmission channel) occupied by some form of signal, whether it is broadcast television, voice, fax data, etc. Signals require a certain size and location of bandwidth in order to be transmitted. The higher and wider the bandwidth, the faster the signal transmission; so if you want to transmit a complex signal such as audio or video, a high amount of bandwidth is a must. Traditionally, bandwidth is seen as a limited space, when one user is occupying it, others must wait their turn. But new technologies are allowing transmitters to send multiple signals in the same amount of bandwidth without getting them confused. This technique is known as multiplexing. And colloquially, bombarding the Internet with unnecessary information is referred to as "taking up bandwidth." For a clear example of this, visit my homepage.

Baud

A standard measure of the speed of data tranmission, or the number of the thousands of bits transmitted per second. For example, many people today use 14.4 baud modems - in other words, modems that can send and receive data as fast as 14,400 bits per second.

Bit

A single piece of data, either an 0 or 1. Eight bits make up one byte. Bits are the most basic and essential elements in digital transmission. Coined by John Tukey in 1949.

BPS

Bits Per Second. The speed at which data is transmitted over a channel. The higher the BPS, the faster the transmission rate. Sometimes known as throughput. Modem speed is measured in BPS, but in these cases, the metric is referred to as baud.

Broadband

Signals in the two gigahertz and above range. These signals are very fast and will be used for personal communications services (PCS) such as digital cellular phones and wireless internet access.

Browser

A software tool used to read electronic documents over the World Wide Web. Netscape is one of the most popular browsers, while people with very slow Internet connections sometimes still use Lynx for text-based web browsing.

Byte

Eight bits of data. A byte usually equals approximately one character from a keyboard. Coined by Werner Bucholtz in the 1950s as a way of representing a bite of bits, but he chose to spell it as byte to avoid confusion with the word bite.

Catagory 3

Short for Category 3 Unshielded Twisted Pair. A standard for copper wiring that can transmit voice, as well as some electronic data.

Catagory 5

Short for Category 5 Unshielded Twisted Pair. A standard for copper wiring designed specifically for electronic data.

Channel

Any medium through which information can be transmitted. For example, the air is a channel for our voices just as much as a fiber optic line can be data for a video signal.

Charter School

A school within a community that has developed a direct educational mandate for itself, which when approved by the state legislature, allows that school to act independently from its designated school district. Charter Schools thus have extreme flexibility when it comes to experimentation, but they are also easily held accountable for their actions - ie, they could lose their charter if their efforts fall short.

Coaxial Cable

Commonly known as cable wire. A standard copper transmission wire made up of an inner and outer wire.

Codec

A product that codes and decodes audiovisual data for digital transmission.

Common Carrier

A telecommunications company that offers communication transmission services required by the FCC to be universally affordable to everyone. Telephone companies are current examples; cable companies are around the corner.

Contract School

A public school which has contracted out its day-to-day managing and reforming to a private (and often for-profit) company.

CWEIS

Community-Wide Education and Information Services. A national program sponsored by the Corporation for Public Broadcasting that is developing local civic networking services in 12 communities.

Cyberspace

The nebulous virtual space where humans interact over computer networks. (the Internet is often referred to as Cyberspace.) Coined by William Gibson in Neuromancer.

Dedicated Line

See Leased Line

Digital

Any technology which converts or transmits information signals by breaking them down into a series of 0's and 1's. Digital transmission has the added advantage of creating a virtual carbon copy of the original, with zero degradation.

Distance Education

Teaching and/or learning long distance by way of telecommunications. For example, a teacher in North Dakota may use the Internet to work with students in Florida.

Download

To copy a program or any form of data from another computer to your own computer.

E-Mail

Electronic mail messages sent over a computer network.

Ethernet

A popular protocol for linking computers over a local area network. Developed by Bob Metcalfe in the1970s.

FAQ

Frequently Asked Questions. A collection of information on the basics of any given subject. Often put together and archived on a server so that people don't waste bandwidth asking simple questions.

Fiber Optics

A high speed channel for transmitting data. Made of high-purity glass sealed within an opaque tube. Much faster than convential copper wire such as coaxial cable.

Flame

An insulting or personal attack in an Internet discussion. Both very common and very annoying.

Followup

A response to a question posted in a USENET or listserv group.

Frame

A small bundle of data transmitted over a local area network. Essentially the same thing as a packet, but frames are packets that occur on LANs only.

Free-Nets

Community-based organizations which offer Internet access to the public at little or no cost. Free-Net was a servicemark of the National Public Telecommunications Network until NPTN declared bankruptcy in 1996.

Frequency

A measurement of the number of electromagnetic waves that pass over a given point in a given period of time.

FTP

File Transfer Protocol. An accepted standard that allows network users to transfer their computer data to each other's computer.

Gateway

A relaying system that allows connectivity between two or more computer networks. For example, America Online serves as a gateway for its users to the Internet, though it is not directly on the Internet in its own right.

Gigabit

1,000,000,000 bits of data.

Gopher

An Internet protocol which allows a user to navigate the Internet through an interfinite series of nested information. Created at the University of Minnesota, home of the Golden Gophers.

Hertz

A unit of frequency equal to one electronmagnetic wave (or cycle) per second. Sound, light, and energy all transmit through these waves.

HTML

Hypertext Markup Language. A convention of codes used to access documents over the World Wide Web. Without HTML codes, a document would be unreadable by a Web browser.

HTTP

Hypertext Transfer Protocol. The protocol used to signify an Internet site is a World Wide Web site. It's seen in all Web addresses, http://www.cnn.com or http://www.cpb.org.

Hypertext

A document that has been marked up to allow a user to select words or pictures within the document, click on them, and connect to further information. An essential element of the World Wide Web.

IAB

The Internet Architecture Board. The standardization committee of ISOC. Created the IP protocol.

IITF

The Information Infrastructure Task Force. A working group formed by the Department of Commerce to discuss policy and planning for the NII.

Information Superhighway

Catchphrase used to describe a futuristic system of universal, internetworked communication services. Attributed to Vice President Al Gore as early as 1979. Officially known in the US as the NII, or National Information Infrastructure.

Internet

The largest international computer network, made of scores of smaller networks linked together by internationally accepted protocols.

IP

The Internet Protocol. The international standard for addressing and shipping data on the Internet.

IRC

Internet Relay Chat, or just Chat. An on-line group discussion.

ISDN

Intergrated Services Digital Network. A service which sends digital signals over telephone lines. Requires special hardware and software at both ends, and is much faster than standard telephone transmission.

ISO

The International Standardization Organization. A group of researchers who have formulated a new Internet protocol called ISO/OSI which could conceivably replace the IAB's IP standard (depending on whom you ask).

ISOC

The Internet Society. An international group of volunteers who coordinate Internet research and development. Within the ISOC is the IAB.

ITFS

Instructional Television Fixed Service. A service provided by one or more microwave stations used for public education and instruction.

LAN

Local Area Network. A group of computers that are locally connected on a network.

Leased Line

A continuously-connected telephone line, primarily used for Internet activity. Usually purchased by moderate to large Internet users, leased lines are often known as dedicated lines.

Listserv

A proprietary e-mail distribution program that allows multiple computer users send messages to a single address and then have that message forwarded to large groups of people. Thousands of listservs of all possible subjects populate the Internet. Often referred to as lists, mailing lists, and e-lists.

Link

The result of HTML markup, a link signifies to a browser that data within a document will automatically connect with either nested data or an outside source. Used in the design of hypertext.

Lynx

A text-based World Wide Web browser. Because it does not employ a graphics capability, it allows slower computers (or computers using a modem) to access the Internet with ease. One of the earliest Internet browsers.

Markup

Text or codes added to a document to convey information about it. Usually used to formulate a document's layout, or to create links to other documents or information servers. HTML and SGML are common forms of markup.

Megabit

1,000,000 bits of data.

Microwave

The Bandwidth of the electromagnetic spectrum ranging above one gigahertz, used for high-speed wireless data transmission.

MIME

Multipurpose Internet Mail Extensions. Programs which work in sync with the Internet, such as an email program.

MMDS

Multichannel Multipoint Distribution Service. A form of wireless cable service that transmits signals at high frequencies. Sometimes referred to as "Wireless Cable." When transmitting analog signals, MMDS can handle 33 channels of television. When the signal is compressed to be sent as a digital signal, it can send as many as 300 channels.

Modem

The hardware used by most personal computers to transmit data over telephone lines.

Mosaic

Formerly the most popular World Wide Web browser. Originally developed at the University of Illinois in 1993, Mosaic has now been licensed to a private company, Spyglass Incorporated.

Multimedia

Any document which uses multiple forms of communications media, such as text, audio, or video.

Multiplexing

Multiplexing is an engineering technique that allows multiple signals to occupy the same amount of bandwidth. Often this is done by breaking up signals and allowing pieces of each signal to take their turn through a particular channel. Or, one signal may be superimposed over a second signal, and then separated when it reaches its destination. Megasized movie theatres also sometimes call themselves multiplexes, but that has nothing to do with signal processing, of course.

Nesting

Placing documents within other documents. Nesting allows a user to access material in a non-linear fashion - this is the primary factor needed for developing hypertext.

Netscape

Currently the most popular web browser, though others are quickly catching up. Interestly, Netscape was developed by the Mosaic Corporation (now known as the Netscape Corporation), made up of programmers that authored the Mosaic web browser.

Network

Any collective of computers that can communicate and exchange data with each other.

NII

The National Information Infrastructure. The official name of the ever-evolving communications network that will interconnect all aspects of society and telecommunications. Commonly known as the Information Superhighway. The Internet is now one of the clearest examples of the NII.

NREN

The National Research and Education Network. A committee of government agencies and researchers in the U.S. determined to unify computer networks into a singular, high speed system. NREN appears to be evolving into a next-generation Internet called Internet 2, which will employ incredibly high speed communications for education and research.

NSF

The National Science Foundation. A US government agency that funds research in science and science education.

NSFNET

The National Science Foundation Network. Often misconstrued as the Internet itself, NSFNET was actually only one of the major networks within the Internet. It was officially decommissioned in 1996, because the enormous growth of private-sector networks made it redudant.

Online

Active and prepared for operation. Nowadays it suggests connected access to a computer network, but originally it was a military term, as in the troops are on line and ready to kill some enemy types.

Open Platform

A computer and network design concept that dictates that all users of the Internet will have the ability to access, create, and publish information, as well as understand each others' information.

OSI

Open Systems Interconnect. The ISO's new Internet protocol. Still under development.

Packet

A bundle of data transmitted over a network. Packets have no set size - they can range from one character to hundreds of characters. To transmit data, the Internet's IP/TCP protocol divides data into packets to improve efficiency.

PCS

Personal Communication Services. A broad range of radio communication services for personal use. Includes wireless faxes, paging systems, digital cellular phones, etc.

POTS

Plain-Old Telephone Service. Telecomspeak for a standard telephone connection. These connections were designed for the transmission of the human voice, and not high-speed data, so they are not very efficient when it comes to network use.

PPP

A software protocol which allows a user to have a direct connection to the Internet over a telephone line. PPP is quickly replacing an older standard, SLIP.

Protocol

A definition or a standard designed to allow different computers and different networks to communicate with each other.

Public Access

Also known as public right-of-way, public access is the notion that all citizens have the right to produce and disseminate information publically over all forms of media.

RFC

Request for Comments. Documents which have been published publically in order to foster discussion on a given subject. The Internet's various protocols have all been developed through the RFC process.

Ring

A term used to describe a local area network that connects a group of computers one after another until they form a ring.

Router

A relay that connects a local area network with other networks.

School Choice

A broad education reform concept of allowing greater decisionmaking flexibility, including parentally-determined attendance, localized management, and private school vouchers.

Server

A computer (or a program) tjat allows other computers to access information on it.

SGML

Standard Generalized Markup Language. The International standards for electronic document markup. HTML is a form of SGML.

SLIP

Serial Line Internet Protocol. Allows a user to connect to the Internet directly over a high-speed modem.

SONET

Synchronous Optical Network. A protocol for transmitting data at high speeds based on multiples of T3 lines. SONET can currently handle as much as 9.6 gigabits per second.

Spectrum

The range of electromagnetic frequencies used for all forms of transmission.

Spread Spectrum

A method of transmitting wireless signals over long distances. The transmitter spreads the signal over a wide bandwith of spectrum, which means it's easier to be picked up by radio receivers, even if it's transmitted at very low power. The idea for spread spectrum was actually developed by none other than Hedy Lamarr. The actress was finally recognized for her achieveents in radio engineering in 1996 with a lifetime achievement award from the EFF.

Star

A term used to describe a local area network that connects a group of computers to a central point, so it forms the shape of a star. Well, sort of like a star. More like a point with lots of lines jutting out of it to other points.

Surfing

Netspeak for exploring content, whether one is surfing through cable stations or surfing the Internet.

Systemic Reform

Macro-level education reform which legislates change through pre-determined outcomes.

10BASE-T

A protocol that allows computers to be connected into a LAN by means of twisted pair wiring.

T1

A telephone company protocol that allows for the transmission of 24 channelsof voice communications at the same time. When used as one channel, T1 has the throughput of around 1.5 megabits per second. Also known as DS-1.

T2

A telephone company protocol that allows for the transmission of 96 channelsof voice communications at the same time. A T2 line is the equivalent of 4 T1 lines. When used as one channel, T2 has the throughput of 6.312 megabits per second. Also known as DS-2.

T3

A telephone company protocol that allows for the transmission of 672 channelsof voice communications at the same time. A T3 line is the equivalent of 28 T1 lines, or 7 T2 lines. When used as one channel, T3 has the throughput of 44.736 megabits per second. Also known as DS-3.

TCP

Transmission Control Protocol (also known as IP/TCP). A protocol that makes sure that a computer's packets of data are shipped and received over a network in their intended order.

Telecommuting

Working at home but connecting to one's office by way of a computer network.

TELNET

Terminal Emulation. The protocol (or the software that uses the protocol) that allows you to connect into another computer elsewhere over the Internet.

Throughput

The speed at which data in transmitted through a channel. Often measured in bits per second.

Token Ring

A term used to describe a Ring local area network that connects a group of computers one after another until they form a ring. Each computer on the ring can send data over the LAN only when it receives a 'token' - essentially, the token travels along the ring, giving each computer the chance to send its data.

Twisted Pair

Standard copper wiring used for telephone lines. The name comes from the fact that the wiring contains a pair of wires that are twised, which helps increase transmission efficiency.

Universal Service

The notion of offerering basic telecommunication services at reasonable prices to all consumers. Telephones, for example, are considered at the level of universal service. The Internet, to date, is not, though it has now been mandated by Congress for schools, libraries, and healthcare institutions.

UNIX

A complicated operating system which played a key role in the development of the Internet. Initially, Internet users had to know UNIX to receive data. Now, browsers and protocols such as the World Wide Web allow any non-technical person to take advantage of the Internet.

URL

Uniform Resource Locator. An Internet address for a gopher, ftp, or Web site. URL does not stand for Universal Resource Locator, as many people believe.

USENET

The network of thousands of Internet "newsgroups" - online discussion groups that can be accessed through a server connected to USENET.

VERONICA

An early searching tool within gopher which allowed a user to type in and retrieve subjects by a key word search.

WAN

Wide Area Network. A network that covers a large region of space, such as a county or a state.

Wavelength

The length of one complete electromagnetic wave, measured usually from crest to crest or trough to trough of successive vibrations.

World Wide Web

Also known as WWW, W3, or the Web. A sophisticated, yet easy-to-use protocol for navigating the Internet by means of hypertext.


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