Glossary of Internet Terms

As with any industry, the Internet has a particular terminology all its own. Below is a glossary of common Internet terms.

ACM: Association for Computer Machinery: A group established in 1947 to promote professional development and research on computers.
address: There are two separate uses of this term in Internet networking: "electronic mail address" and "Internet address." An electronic mail address is the string of characters that you must give an electronic mail program to direct a message to a particular person. See "Internet address" for its definition.
AI: Artificial Intelligence: The branch of computer science which deals with the simulation of human intelligence by computer systems.
AIX: Advanced Interactive Executive: IBM's version of Unix.
ANSI: American National Standards Institute: A group that defines U.S. standards for the information processing industry. ANSI participates in defining network protocol standards.
ARCHIE: A system for locating files that are publicly available by anonymous FTP.
ARP: Address Resolution Protocol: An Internet protocol which runs on Ethernets and Token Rings and maps Internet addresses to MAC addresses.
ARPA: Advanced Research Projects Agency: The former name of what is now called DARPA.
ARPANET: Advanced Research Projects Agency Network: A pioneering long haul network funded by ARPA. It served as the basis for early networking research as well as a central backbone during the development of the Internet. The ARPANET consisted of individual packet switching computers interconnected by leased lines.
AS: Autonomous System: A collection of gateways (routers) under a single administrative authority using a common Interior Gateway Protocol for routing packets.
ASCII: American Standard Code for Information Interchange.
B: Byte: One character of information, usually eight bits wide.
b: bit - binary digit: The smallest amount of information which may be stored in a computer.
baud: When transmitting data, the number of times the medium's "state" changes per second.
BBN: Bolt, Beranek, and Newman, Inc.: The Cambridge, MA, company responsible for development, operation and monitoring of the ARPANET, and later, the Internet core gateway system, the CSNET Coordination and Information Center (CIC), and NSFnet Network Service Center (NNSC).
BITNET: Because It's Time Network: BITNET has several thousand host computers, primarily at universities and in many countries. It is managed by EDUCOM, which provides administrative support and information services. There are three main constituents of the network: BITNET in the United States and Mexico, NETNORTH in Canada, and EARN in Europe. There are also AsiaNet in Japan and connections in South America. See CREN.
bps: bits per second: A measure of data transmission speed.
BSD: Berkeley Software Distribution: Term used when describing different versions of the Berkeley UNIX software, as in "4.3BSD UNIX."
catenet: A network in which hosts are connected to networks with varying characteristics, and the networks are interconnected by gateways (routers). The Internet is an example of a catenet.
CCITT: International Consultative Committee for Telegraphy and Telephony, an international standards board.
CNRI: Corporation for National Research Initiatives.
core gateway: Historically, one of a set of gateways (routers) operated by the Internet Network Operations Center at BBN. The core gateway system forms a central part of Internet routing in that all groups must advertise paths to their networks from a core gateway.
COSINE: Cooperation for Open Systems Interconnection Networking in Europe
CREN: The Corporation for Research and Educational Networking: COREN, BITNET and CSNET have recently merged to form CREN.
CSNET: Computer + Science Network: A large data communications network for institutions doing research in computer science. It uses several different protocols including some of its own. CSNET sites include universities, research laboratories, and commercial companies. See CREN.
CSU: Channel Service Unit.
DARPA: U.S. Department of Defense Advanced Research Projects Agency: The government agency that funded the ARPANET and later started the Internet.
datagram: The unit transmitted between a pair of Internet modules. The Internet Protocol provides for transmitting blocks of data, called datagrams, from sources to destinations.
DCA: Defense Communications Agency: The government agency responsible for installation of the Defense Data Network (DDN), including the ARPANET and MILNET lines and PSNs. Currently, DCA administers the DDN, and supports the user assistance and network registration services of the DDN NIC.
DDN: Defense Data Network: Comprises the MILNET and several other Department of Defense networks.
DDN NIC: The network information center at SRI International. It is the primary repository for Request for Comments (RFC) and Internet drafts, as well as providing other services.
DECNET: Digital Equipment Corporation network: A networking protocol for DEC computers and network devices.
dedicated line: A permanently connected private telephone line between two locations.
default route: A routing table entry which is used to direct any data addressed to any network numbers not explicitly listed in the routing table.
DOD: U.S. Department of Defense.
DOE: U.S. Department of Energy.
download: To transfer files from one computer to another.
DNS: Domain Name System: A mechanism used in the Internet for translating names of host computers into addresses. The DNS also allows host computers not directly on the Internet to have registered names in the same style.
DS-1: Digital Service - Level 1. See T-1.
DS-3: Digital Service - Level 3. See T-3.
DSU: Digital Service Unit.
EARN: European Academic Research Network: One of three main constituents of BITNET.
EASI: European Academic Supercomputing Initiative.
EBCDIC: Extended Binary-Coded Decimal Interchange Code.
EGP: External Gateway Protocol: A protocol which distributes routing information to the routers and gateways which interconnect networks.
email: The vernacular abbreviation for electronic mail.
ESF: Extended Superframe.
Ethernet: A network standard for the hardware and data link levels. There are two types of Ethernet: Digital/Intel/Xerox (DIX) and IEEE 802.3.
FAQ: Frequently Asked Questions: A list with their answers. Most mailing lists and all network newsgroups provide FAQ postings on a regular basis.
FDDI: Fiber Distributed Data Interface: FDDI is a high-speed (100 Mb) token ring LAN.
FIPS: Federal Information Processing Standard.
FTP: File Transfer Protocol: The Internet standard high-level protocol for transferring files from one computer to another.
gateway: A special-purpose dedicated computer that attaches to two or more networks and routes packets from one network to the other. In particular, an Internet gateway routes IP datagrams among the networks it connects. Gateways route packets to other gateways until they can be delivered to the final destination directly across one physical network. See router.
GB: Gigabyte: A unit of data storage size which represents one billion characters of information.
Gb: Gigabit: One billion bits of information (usually used to express a data transfer rate; as in, 1 gigabit/second = 1Gbps).
GNU: Gnu's Not UNIX: A UNIX-compatible operating system developed by the Free Software Foundation.
Gopher: A menu-based system for exploring Internet resources.
header: The portion of a packet, preceding the actual data, containing source and destination addresses and error-checking fields.
host number: The part of an Internet address that designates which node on the (sub)network is being addressed.
HYPERchannel: High-speed communications link.
I/O: Input/Output.
IAB: Internet Activities Board: The IAB is the coordinating committee for Internet design, engineering and management.
ICMP: Internet Control Message Protocol: ICMP is an extension to the Internet Protocol. It allows for the generation of error messages, test packets, and informational messages related to IP.
IDNX: Integrated Digital Network Exchange.
IEEE: Institute for Electrical and Electronics Engineers.
IESG: Internet Engineering Steering Group.
IETF: Internet Engineering Task Force: The IETF is a large open community of network designers, operators, vendors, and researchers whose purpose is to coordinate the operation, management and evolution of the Internet, and to resolve short- and mid-range protocol and architectural issues. It is a major source of proposed protocol standards which are submitted to the Internet Activities Board for final approval. The IETF meets three times a year and extensive minutes of the plenary proceedings are issued.
internetwork: Any connection of two or more local or wide-area networks.
Internet: The global collection of interconnected regional and wide-area networks which use IP as the network layer protocol.
Internet address: An assigned number which identifies a host in an internet. It has two or three parts: network number, optional subnet number, and host number.
IP: Internet Protocol: The network layer protocol for the Internet. It is the datagram protocol defined by RFC 791.
IRTF: Internet Research Task Force: The IRTF is a community of network researchers, generally with an Internet focus. The work of the IRTF is governed by its Internet Research Steering Group (IRSG).
ISO: International Standards Organization.
JvNC: John von Neumann National Supercomputer Center.
KB: Kilobyte: A unit of data storage size which represents 1,024 characters of information.
Kb: Kilobit: 1,024 bits of information (usually used to express a data transfer rate; as in, 1 kilobit/second = 1Kbps).
KNET: Kangaroo Network: Hardware/software product (Spartacus/Fibronics) that enables IBM mainframes to communicate over networks with the TCP/IP protocol suite.
Knowbot: An experimental information-retrieval tool; a "knowledge robot" or "robot librarian."
LAN: Local Area Network: A network that takes advantage of the proximity of computers to offer relatively efficient, higher speed communications than long-haul or wide-area networks.
LISP: List Processing Language.
MAC: Medium Access Control: For broadcast networks, it is the method which devices use to determine which device has line access at any given time.
MAN: Metropolitan Area Network.
MB: Megabyte: A unit of data storage size which represents one million characters of information.
Mb: Megabit: One million bits of information (usually used to express a data transfer rate; as in, 1 megabit/second = 1Mbps).
MILNET: Military Network: A network used for unclassified military production applications. It is part of the Internet.
MTTF: Mean Time to Failure: The average time between hardware breakdown or loss of service. This may be an empirical measurement or a calculation based on the MTTF of component parts.
MTTR: Mean Time to Recovery: The average time it takes to restore service after a breakdown or loss. This is usually an empirical measurement.
MVS: Multiple Virtual Storage: An IBM operating system based on OS/1.
modem: A piece of equipment that connects a computer to a data transmission line (typically a telephone line).
NASA: National Aeronautics and Space Administration.
NBS: National Bureau of Standards: Now called NIST.
network number: The part of an internet address which designates the network to which the addressed node belongs.
NFS: Network File System: A network service that lets a program running on one computer to use data stored on a different computer on the same internet as if it were on its own disk.
NIC: Network Information Center: An organization which provides network users with information about services provided by the network.
NII: National Information Infrastructure.
NIST: National Institute of Standards and Technology: Formerly NBS.
NOC: Network Operations Center: An organization which is responsible for maintaining a network.
NREN: National Research and Education Network.
NSF: National Science Foundation.
NSFNET: National Science Foundation Network: A high-speed internet that spans the country, and is intended for research applications. It is made up of the NSFnet Backbone and the NSFnet regional networks. It is part of the Internet.
NSFNET Backbone: A network connecting 21 sites across the continental United States. It is the central component of NSFnet.
NSFNET Mid-Level: A network connected to the highest level of the NSFNET that covers a region of the United States. It is to mid-level networks that local sites connect. The mid-level networks were once called "regionals."
NSFNET Regional: A network connected to the NSFnet Backbone that covers a region of the United States. It is to the regionals that local sites connect.
NSS: Nodal Switching Subsystem.
NYSERNET: New York State Educational and Research Network: An internet which serves NY educational and research institutions. It also serves as the NSFnet regional network for New York state.
OSI: Open Systems Interconnection: A set of protocols designed to be an international standard method for connecting unlike computers and networks. Europe has done most of the work developing OSI and will probably use it as soon as possible.
OSI Reference Model: An "outline" of OSI which defines its seven layers and their functions. Sometimes used to help describe other networks.
OSPFIGP: Open Shortest-Path First Internet Gateway Protocol: An experimental replacement for RIP (Routing Interchange Protocol). It addresses some problems of RIP and is based upon principles that have been well-tested in non-Internet protocols. Often referred to simply as OSPF.
packet: The unit of data sent across a packet switching network. The term is used loosely. While some Internet literature uses it to refer specifically to data sent across a physical network, other literature views the Internet as a packet switching network and describes IP datagrams as packets.
PCNFS: Personal Computer Network File System.
POSIX: Portable Operating System Interface: Operating system based on UNIX.
PPP: Point-to-Point Protocol: provides a method for transmitting datagrams over serial point-to-point links.
protocol: A formal description of message formats and the rules two computers must follow to exchange those messages. Protocols can describe low-level details of machine-to-machine interfaces (e.g., the order in which bits and bytes are sent across a wire) or high-level exchanges between allocation programs (e.g., the way in which two programs transfer a file across the Internet).
PSC: Pittsburgh Supercomputing Center.
PSCNET: Pittsburgh Supercomputing Center Network.
PSN: Packet Switch Node: An Internet Packet Switch. Also, a switching node in the X.25 architecture. This acronym is also commonly used as an expression for "packet-switched network."
PSP: Packet Switching Processor.
RCP: Routing Control Processor.
RFC: The Internet's Request for Comments documents series: The RFCs are working notes of the Internet research and development community. A document in this series may be on essentially any topic related to computer communication, and may be anything from a meeting report to the specification of a standard.
RIP: Routing Interchange Protocol: One protocol which may be used on internets simply to pass routing information between gateways. It is used on many LANs and on some of the NSFnet regional networks.
RISC: Reduced Instruction Set Computing.
RJE: Remote Job Entry: The general protocol for submitting batch jobs and retrieving the results.
RLOGIN: Remote Login: A service on internets very similar to TELNET. RLOGIN was invented for use between Berkeley Unix systems on the same LAN at a time when TELNET programs didn't provide all the services users wanted.
router: A special-purpose dedicated computer that attaches to two or more networks and routes packets from one network to the other. In particular, an Internet gateway routes IP datagrams among the networks it connects. Gateways route packets to other gateways until they can be delivered to the final destination directly across one physical network.
RPC: Remote Procedure Call: An easy and popular paradigm for implementing the client-server model of distributed computing.
server: A computer that shares its resources, such as printers and files, with other computers on the network. An example of this is a Network Files System (NFS) Server which shares its disk space with a workstation that does not have a disk drive of its own.
SESQUINET: Sesquicentennial Network: Texas-based regional network named for their sesquicentennial celebration.
SLIP: Serial Line Internet Protocol: SLIP is currently a defacto standard, commonly used for point-to-point serial connections running TCP/IP. It is not an Internet standard but is defined in RFC 1055.
SMTP: Simple Mail Transfer Protocol: The Internet standard protocol for transferring electronic mail messages from one computer to another. SMTP specifies how two mail systems interact and the format of control messages they exchange to transfer mail.
SNA: System Network Architecture: IBM's data communications protocol.
SNMP: Simple Network Management Protocol: The SNMP (RFC 1157) is the Internet's standard for remote monitoring and management of hosts, routers, and other nodes and devices on a network.
subnet: A portion of a network, which may be a physically independent network, which shares a network address with other portions of the network and is distinguished by a subnet number. A subnet is to a network what a network is to an internet.
subnet number: A part of the Internet address which designates a subnet. It is ignored for the purposes of Internet routing, but is used for intranet routing.
SURANET: Southeastern Universities Research Association Network: An NSFNET regional network.
T1: A term for a digital carrier facility used to transmit a DS-1 formatted digital signal at 1.544 megabits per second.
T3: A term for a digital carrier facility used to transmit a DS-3 formatted digital signal at 44.746 megabits per second.
TCP: Transmission Control Protocol: A transport layer protocol for the Internet. It is a connection-oriented, stream protocol defined by RFC 793.
TCP/IP: Transmission Control Protocol/Internet Protocol: This is a common shorthand which refers to the suite of application and transport protocols which run over IP. These include FTP, Telnet, SMTP, and UDP (a transport layer protocol).
Telenet: A public packet-switching network operated by US Sprint.
TELNET: The Internet standard protocol for remote terminal connection service. Telnet allows a user at one site to interact with a remote timesharing system at another site as if the user's terminal was connected directly to the remote computer.
THEnet: The Texas Higher Education Network: A multiprotocol network connecting most major academic and research institutions in the State of Texas, as well as several institutions in Mexico.
Token Ring: A type of LAN. Examples are IEEE 802.5, ProNET-10/80 and FDDI. The term "token ring" is often used to denote 802.5.
topology: The physical layout of a network.
Tymnet: A public packet-switching network operated by McDonnell Douglas Network Systems Company.
UDP: User Datagram Protocol: A transport layer protocol for the Internet. It is a datagram protocol which simply adds a level of reliability to IP datagrams. It is defined by RFC 768.
ULTRIX: UNIX-based operating system for Digital Equipment Corporation computers.
UNIX: An operating system developed by Bell Laboratories that supports multiuser and multitasking operations.
UUCP: UNIX-to-UNIX Copy Program: A protocol used for communication between consenting UNIX systems.
VMS: Virtual Memory System: A Digital Equipment Corporation operating system.
WAIS: Wide Area Information Server: An Internet service for looking up specific information in Internet databases.
WAN: Wide Area Network.
WESTNET: One of the National Science Foundation funded regional TCP/IP networks that covers the states of Arizona, Colorado, New Mexico, Utah and Wyoming.
WHOIS: An Internet program which allows users to query a database of people and other Internet entities, such as domains, networks, and hosts, kept at the NIC. The information for people shows a person's company name, address, phone number and email address.
WWW: World Wide Web.
XGMON: X-Windows-based Graphical Monitor Prototype.
XNS: Xerox Network System: A data communications protocol developed by Xerox. It uses Ethernet to move the data between computers.
X.25: A data communications protocol developed to describe how data passes into and out of public data communications networks. The public networks such as Telenet and Tymnet use X.25 to interface to customer computers.