New Jersey City University  - Website  

G l o s s a r y

A c a d e m i c   C o m p u t i n g

Welcome

Announcements

Training & Dept. Hours

Suggestion & Comments

Staff

Computer Labs

Loaner Library

Access: Entry to or communication with a particular object, such as an operating system, specific files, or accounts.

Address mask: A bit mask used to select bits from an IP address for subnet addressing. The mask is 32 bits long and selects the network portion of the IP address and one or more bits of the local portion.

Anonymous ftp: See FTP.

ANSI: American National Standards Institute. An organization that sets standards for the U.S. computer industry. ANSI participates in defining network protocol standards for instance.

ARP: Address Resolution Protocol. The TCP/IP protocol used to dynamically bind a high level IP address to a low-level physical hardware address.

ASCII: American Standard Code for Information Interchange. Based on a 7-bit character set, it consists of the first 128 (0-127) characters of the ANSI character set (and most other 8-bit character sets). The ASCII character set is the most universal character-coding set.

ASCII text file: A file that contains nothing but ASCII characters without special formatting. ASCII text files are sometimes used in file transfers.

Backbone: A network that connects other networks.

Baud Rate: Speed at which information is transferred. Generally referred to as bits per second, or bps, now.

BBS: See Bulletin Board System.

Binary file: A file containing information that is in computer-readable form; it can be read only by an application. "Binary_file" usually refers to a file that uses all 8 bits of each byte for information. Text files usually use only 7 bits, leaving the eighth bit as 0.

Binary transfer: Method of transferring files to or from a remote computer in which all eight bits of each byte are transferred. In a text transfer, the eighth bit is ignored.

BinHex: A file format for encoding Macintosh binary files as text files, for easier transfer between computers. BinHex files usually have the suffix ".hqx" Almost all Macintosh communication programs will automatically detect and translate files in BinHex format but PC systems rarely "know" how to translate them. For that purpose a special program called PCBINHEX can be used to translate them from text to binary.

bps: Bits Per Second. Speed at which data is transferred. Often used in discussing the speed of modems and serial transmissions.

Bulletin Board System (BBS): Electronic bulletin boards are computers running with software which allows callers to leave messages and access information much like an actual bulletin board.

CCITT: Comite Consultatif Internationale de Telegraphique et Telephonique. An international committee which sets communications standards. The V.32, V.32bis, V.42, etc. standards for modem speed and compression are CCITT standards. CCITT has been replaced by the ITU.

Client: A computer using services or resources provided by a remote machine, called a server. Often, communications software will have a separate version for the client, or guest, and the server, or host.

Coaxial cable: A type of cable that is commonly used due to its insensitivity to noise interference. Coaxial cable is often used in Ethernet networks; both thick (10Base5) and thin (10Base2) Ethernet cables are coaxial.

COM Port: Also called a serial port. A connection on a PC computer, usually named COM1 or COM2, where you plug in the cable for a serial device. Common serial devices are printers and modems. Serial ports are smaller than parallel ports and usually contain nine pins.

Concentrator: Permits you to position computers closer together on the network cable than you could otherwise. If you use a twisted-pair cable, you need a concentrator.

Daemon: An agent program that runs continuously and provides resources to client systems on the network.

Domain: Part of the Internet Protocol (IP) address, used to identify the organization or local network that a local host is connected to. For example: MSN.COM

Download: Wallpaper is a graphic image designed for decorating your computer's desktop. If it's on your Web page, it's called a background.

Electronic Mail (Email): A method of transferring information (often text messages) from one computer to another over a network.

Ethernet: A popular networking technology featuring 10Mbps transmission speeds, running over thin coaxial (10Base-2), thick coaxial (10Base-5), or twisted pair (10Base-T) cables. Ethernet will support TCP/IP, Novell Netware, and other communication protocols.

Ethernet address: An Ethernet address is a six-part hexadecimal number in which a colon separates each part (for example, 8:0:20:1:2e:0). This number indicates that an Ethernet communications board is installed in a PC and is used to identify the PC as a member of the network.

Each Ethernet board has, in theory, a unique number as provided by the vendor in the board's firmware.

File Server: A computer that provides networked computers with access to shareable resources. A dedicated file server can be used only as a file server while it is on the network. A non-dedicated file server can be used simultaneously as a file server and a workstation.

File Sharing: Provisions in the networking system software that allow more than one user to access the same file.

Flow Control: Also called handshake. The processes used to regulate the rate at which information is transferred from one device to another. One device sends a signal to the other when information can be transferred.

Freeware: Software that is provided without charge. Contrast with shareware.

FTP: File Transfer Protocol. Allows users to copy files between the local system and any system reachable over the network. Every UNIX system has FTP and there are versions for Macintosh and Windows. A common way to make software (text files, sounds, pictures, utilities, etc.) available is to put it on an anonymous FTP server. Anonymous FTP servers allow users to log on without a password, specify "guest" as the user, and then copy whatever has been made available.

Gateway: Transfers information between physically separate networks that are based on differing protocols. It performs high-level information translation, while routers provide low-level.

GIF: Graphic Interchange Format. A popular file format for graphic images, created by CompuServe. The GIF format features image compression.

Internet: A worldwide collection of interconnected networks, providing a wide variety of services, using the TCP/IP network protocols.

IP: The TCP/IP standard protocol that defines the IP as a unit of information passed across an Internet and provides the basis for packet delivery service. IP includes the ICMP control and error message protocol as an integral part. The entire protocol suite is often referred to as TCP/IP because TCP and IP are the two most fundamental protocols.

Java: A platform-independent programming language, produced by Sun Microsystems. Java is built as a method to provide services over the WWW. With Java, a Web site provides a Java application (called an applet) which is downloaded by the client and executed on the client computer. Java is specifically built so that an application can be run on any kind of system. A separate Mac, Windows, Sun, etc. version is not needed. Java also has some security features built in to make it more difficult for destructive applets to be written. Java is based on a subset of the C programming language.

JPEG: A format for compressed graphic images, which produces much smaller files than GIFs. The compression algorithm is a lossy one, however, which will not reproduce the original image exactly. Various settings are available to allow more compression at the cost of a greater loss of image quality.

LAN: Local Area Network. A group of personal computers linked together in order to share programs, data, and peripherals.

Mbps: Megabits per second (one million bits per second). Speed at which data is transferred.

Modem: Modulate-Demodulate. A communications device that enables a computer to transmit information over a telephone line.

NetBIOS: Network Basic Input/Output System. It provides a Session Layer interface between network applications running on a PC and the underlying protocol software of the Transport and Network Layers.

NETBUI: The NetBIOS Extended User Interface. This is the transport layer driver frequently used by LAN Manager.

NetWare: A network operating system developed by Novell.

Network: A group of computers connected by cables or other means and using software that enables them to exchange information and share equipment (such as printers and disk drives).

Network address: A unique number associated with a host that identifies it to other hosts during network transactions.

NFS: Network File System. A protocol developed by SUN Microsystems that uses IP to allow a set of computers to access each other's file systems as if they were local.

NIC: Network Information Center. The NIC at SRI international in Menlo Part, Calif., assigns IP addresses and network numbers per request submitted by an organization. The number assigned is appropriate to the number of host devices on the network.

Node: A personal computer hooked up to a network. Any network station.

PING: The Packet Internet Groper is a program that is useful for testing and debugging networks. It sends an echo packet to the specified hosts, and waits for a response. It reports success or failure and statistics about its operation.

POP: Post Office Protocol. A protocol to allow single user computers to download email from a server.

PPP: Point to Point Protocol. An implementation of the TCP/IP protocol to be used over serial lines (modems). Allows direct access to the Internet over a modem. Compare with SLIP, another such protocol.

Protocol: Rules for communicating, particularly for the format and transmission of data. Most protocols are transparent. For instance a protocol was employed to transfer this information to your computer.

Real Audio: A software system for playing sound files in real time over the Internet. Produced by Progressive Networks.

Repeater: A device used in networks to extend cabling distances by amplifying or regenerating signals. Used to join lengths of network cables, or to split a network cable into multiple segments. You might also find repeaters useful if you want to use different types of cable in your network. For example, you could connect an Ethernet network with 10Base-T cable to one on a thick cable.

Router: Hardware and software that routes data between similar or dissimilar networks on the protocol level. Routers can support more than one protocol. Routers can actively direct messages between separate networks (for example, an Ethernet network and a token ring network). They make decisions about which path through the network traffic will follow. Each network connected by the router has a unique identity with its own Internet address.

Serial Interface: An interface between a computer and a serial device, such as a printer or modem, by which the computer sends single bits of information to the device, one after the other.

Server: A network device that provides services to client stations. Servers include file servers, disk servers, print servers, etc.

Shareware: Publicly distributed software, for which the author requests payment. Payment may or may not buy additional functionality or support.

SLIP: Serial Line Internet Protocol. An implementation of the TCP/IP protocol to be used over serial lines (modems). Allows direct access to the Internet over a modem. Compare with PPP, another such protocol.

SMTP: Simple Mail Transfer Protocol. The protocol used to transfer email between computers on the Internet. It is a server-to-server protocol, so other protocols (like POP) are needed to transfer the email to a client computer.

SNMP: Simple Network Monitoring Protocol. A standard protocol used to monitor network activity on "agent" nodes from management stations.

TCP/IP: Transmission Control Protocol/Internet Protocol. TCP/IP allows a process on one computer to send data to a process on another computer using the IP protocol. TCP can be used as a full duplex or one-way simplex connection.

Thick Ethernet: Ethernet cabling that uses half-inch diameter coaxial cable to connect computers. The connector, DB-9, resembles a serial port.

Thin Ethernet: Ethernet cabling that uses thin coaxial cable to connect computers. Uses a T-shaped connector.

Token Ring: A networking hardware system developed by IBM. Constructed as a ring of daisy-chained nodes. Each node passes a control message (token) around the ring. The node that has the token can send a message.

Topology: The physical layout of network cabling.

Twisted Pair Wire: Commonly used for telephone and network wiring. Twisted pair consists of two pairs of wires one for transmitting and one for receiving data. The wires in each pair are twisted together to reduce induction between them. 10Base-T Ethernet cable is twisted pair.

Usenet: A collection of discussion areas available via the Internet. Usenet provides a large number of "newsgroups" that discuss a wide variety of topics, including technical, computer, scientific, recreational, and social areas. Usenet can be accessed with a number of programs on different computer platforms.

UUencode/UUdecode: A system for encoding binary files as ASCII files for easy transfer between computer systems.

V.DOT terms: A series of modem communications standards:

V.32: Supports standard 9600 bps.
V.32bis: Supports 14,400 bps.
V.42: Supports error detection and data compression.
V.42bis: Supports a different data compression scheme than V.42.
V.34: Supports 28,800 bps.

WAIS: Wide Area Information Server. An information retrieval system used on the Internet, which features text search facilities to identify the documents that the user wants to find.

WAN: Wide Area Network. A network linking computers, terminals, and other equipment over a large geographic area.

Web: See World Wide Web.

Web Browser: A program that accesses the WWW, allowing the user to use the multimedia resources of the Internet. A Web browser will require Internet access (either Ethernet hardware or PPP/SLIP), and sufficient graphics hardware.

World Wide Web (WWW): An amalgam of Internet sites offering text, graphics, sound, and animation resources in an easy to use way, through the HTTP protocol. More generally, all FTP, Gopher, and WAIS sites are also included.

WWW: See World Wide Web.

10Base2: Ethernet running on thin coaxial cable.

10Base5: Ethernet running on thick coaxial cable.

10Base-T: Ethernet running on twisted pair cable. It looks like phone cord but the modular plugs at the end, RJ-45 connectors, are slightly larger.