The purpose of this page is to provide a resource for some of the more common (and some not so common) computer acronyms as well as some common computer terminology. A lot of these acronyms are in common usage on the Internet. Some of them are UT System or even UTD specific acronyms. Hopefully, this page will cut through some of the mystery of computer acronyms and terms and help you understand what technical people are talking about.

I have tried, as much as possible, to steer clear of technical definitions and use layman's terms (so some "purists" may not like my definitions.) Some of the definitions use acronyms or unfamiliar terms too. As much as possible, I've tried to ensure that any acronym or term used in a definition is defined on this page. If you don't find, on this page, an acronym or term that you are looking for, please send me email. I will be happy to add it to the page. You will find much more complete computer acronym and terms resources, with extensive definitions, at the PC Webopaedia and the Free Online Computing Dictionary. If you're looking specifically for security related acronyms and terms, visit the SANS glossary.

ACL - Access Control List - a list that specifies what operations users can perform on files and directories. ACLs are part of the security subsystem of a network OS and are used to grant or deny access to various functions of the OS.
Active X - a Microsoft specification that defines how programs can share information. Active X controls may be written in any programming language, but will only run on the Windows OS.
ADSL - Asymmetric Digital Subscriber Line - the latest in connection technology, at least as fast as cable modems, but uses your existing phone line.
AES - Advanced Encryption Standard - a lightweight encryption algorithm for securing VPNs
AP - Access Point - a device used to connect wireless networks to a wired network.
API - Application Programming Interface - programmers writing applications for an OS will use these to take advantage of already existing capabilities within that OS to make their programs look familiar to the users.
APNIC - Asia Pacific Network Information Centre - the Internet registry organization for the Internet in Asia and the Pacific RIM.
ANSI - American National Standards Institute - for a complete explanation, see the ANSI web site.
ARIN - American Registry for Internet Numbers - the Internet registry service for North and South America, as well the Carribean and sub-Saharan Africa.
ARP - Address Resolution Protocol - the protocol used to convert an IP address to a MAC address.
ARPANET - the Advanced Research Projects Agency Network (kind of a hybrid, compound acronym/shortened-word form) - the beginnings of the Internet. In 1969, the DOD established four nodes outside the military; at UC Santa Barbara and UCLA, SRI International, and the University of Utah. For a nice timeline history of the Internet with lots of acronyms, see Robert H Zakon's page at the Internet Society web site.
ASCII - American Standard Code for Information Interchange - pronounced ask-ee - ASCII is the code that represents characters as numbers so computers can understand them. For example, the upper case letter "A" is 65, which to a computer looks like this - 1000001 - (computers only "understand" 0's and 1's, which is the binary numbering system.) The lower case letter "a" is 97, which is 1100001 in binary.
ASP - Active Server Pages - a Microsoft specification for dynamically created web pages with the .asp extension, which allows programmers to use either Visual Basic or JScript to create web pages "on the fly".
ATM - Asynchronous Transfer Mode - technology that allows much faster data transfer rates than Ethernet - as much as six times as fast.
authentication - the process of identifying an individual through the use of a username and password combination. This ensures that the individual logging in is who they claim to be.


backbone - a term used to describe the underlying infrastructure that connects all the nodes of a network together. In the case of the Internet, it refers to the major telephone and circuit providers who own the cable connecting all the networks worldwide. (AT&T, UUNET, Sprint, MCI Worldcom, BBNPlanet, CWNET, et.al.)
BBS - Bulletin Board Service - the way it used to be. Back in the "good old days", people used to hang out in the bulletin boards and swap stories and files and such. There's still quite a few bulletin boards around, but Usenet and web-based bulletin boards are supplanting them.
BCC - Blind Carbon Copy - when you send email using this line, the recipients' addresses do not appear in the email the recipients receive - spammers do this a lot. Many email clients will display "undisclosed recipients" in the TO: field, if only the BCC line is used to send the message.
BDC - Backup Domain Controller - a backup domain server in an NT domain. The BDC has a duplicate copy of all domain accounts, groups, permissions and login scripts, but is not authoritative for the domain. Depending on network topology, any domain controller may log a user in to the domain.
BGP - Border Gateway Protocol - a routing protocol that allows incremental updating of router tables and enables optimal path determination between peered routers.
BIOS - Basic Input/Output System - the system that gets your computer started, before the OS takes over. It does things like get the keyboard and mouse ready to use.
bit - an abbreviation for "binary digit" - the smallest unit of information a computer can use. It's either a 1 or a 0. (Actually a high or low voltage state.)
BO - Back Orifice - a hacker tool that is normally sent as a trojan horse to an unsuspecting user. When installed, it allows the attacker to take control of the victim's computer and do anything they want, up to and including formatting the hard drive.
broadcast - the process of sending information to all machines on a network. We tend to shy away from protocols that use extensive broadcasting, because they make the network very "busy" (or "chatty" as we geeks say) and therefore slow down data transfers across the network and degrade performance.
byte - an abbreviation for "binary term" - a byte is equal to eight bits and is large enough to hold one character (like an A or the number 1.)

CA - Certificate Authority - a trusted third party used to create digital certificates and private/public key pairs and to guarantee that the party signing a document is the person they claim to be.
cache - a part of memory set aside for temporary storage, like a scratch pad your computer can jot notes on.
CATS - Technology and Communications Services - the division of UTD IR responsible for all campus UNIX server systems, including mail, news, web services, backup services, dialup services, UNIX programming services, campus backbone and wiring infrastructure, audio, video, and data feeds and all telecommunications services for the university.
CC - Carbon Copy
CD - Compact Disk - a polycarbonate/metal disk for storing digital information
CDMA - Code-Division Multiple Access - a digital cellular technology that uses spread-spectrum techniques. Unlike competing systems, such as GSM, that use TDMA, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence. CDMA is a military technology first used during World War II by the English allies to foil German attempts at jamming transmissions. The allies decided to transmit over several frequencies, instead of one, making it difficult for the Germans to pick up the complete signal. Because Qualcomm Inc. created communications chips for CDMA technology, it was privy to the classified information. Once the information became public, Qualcomm claimed patents on the technology and became the first to commercialize it.
CDPD - Cellular Digital Packet Data - a data transmission technology developed for use on cellular phone frequencies. CDPD uses unused cellular channels (in the 800- to 900-MHz range) to transmit data in packets. This technology offers data transfer rates of up to 19.2 Kbps, quicker call set up, and better error correction than using modems on an analog cellular channel.
CD ROM - Compact Disc, Read Only Memory - a CD that, once stamped by the vendor, cannot be written over. The normal storage capacity is 650MB which is about the same amount of storage as 455 floppy discs.
CGI - Common Gateway Interface - the specification for moving data between a web page and a program designed to manipulate or store the data and return information to the web page. Perl is often used for CGI scripts.
CIFS - Common Internet File System - a protocol that allows file sharing across multiple OSes and platforms without any of the computers having to install new software.
CIR - Committed Information Rate - the rate of data transfer that has been guaranteed by the provider of the connection.
CLEC - Competitive Local Exchange Carrier - local telco alternatives to Bell and GTE.
client - a computer program which is used to access a specific application on a server. Also, a name for a program which accesses specific programs on a server (such as an email client that access the mail server.) Sometimes used to refer to computers which depend on a server for their operating system, such as thin clients.
CO - Central Office - where the switchboards and operators used to be. Now it's a bunch of computers (and sometimes older switches that need to be replaced.)
cookies - messages given to a web browser by a server. This creates a text file on your hard drive which allows web sites to track how often you visit, what you look at on their site, and how often you visit. Sometimes it is used to save information about you so you can use the site repeatedly without having to re-identify yourself over and over again.
CPU - Central Processing Unit - the brains of your computer. You know - "Intel Inside"®.
CRACK - Challenge/Response Authentication of Cryptographic Keys - a protocol for the secure exchange of keys, used by Nokia primarily.
CSU/DSU - Channel Service Unit/Data Service Unit - "the DSU is a device that performs protective and diagnostic functions for a telecommunications line. The CSU is a device that connects a terminal to a digital line. Typically, the two devices are packaged as a single unit." (PC Webopaedia)

DARPA - Defense Advanced Research Project Agency - the progenitor of the Internet. DARPA is where it all began.
datagram - a part of a message sent over a network. Similar to a packet.
DBMS - DataBase Management System - a set of programs that allow you to control and manage a database.
DEC - Digital Equipment Corporation - now a part of Compaq Corporation.
DES - Data Encryption Standard - a symmetric key encryption method that was standardized in 1981. Triple DES is a more recent usage of it.
DFS - Distributed File System - a file system mechanism for NT that allows a number of shares to be mapped to one drive letter.
DHCP - Dynamic Host Configuration Protocol - a protocol used to dynamically assign IP addresses and WINS configuration information.
DHTML - Dynamic HyperText Markup Language - HTML with active content added.
DIR - Department of Information Resources - the UT System department responsible for setting computing policy for all components of the UT System.
DISA - Defense Information Systems Agency (also the Data Interchange Standards Association.)
DLL - Dynamic Link Library - a "library" of data or functions which a Windows program uses to complete instructions.
DMA - Direct Memory Access - a method of transferring data to and from peripherals while bypassing the CPU.
DMCA - Digital Millennium Copyright Act - the US enabling legislation which updates US Copyright laws to comply with the World Intellectual Properties Organization treaties, of which the US is a signatory member. See the Crash Course in Copyright for answers to specific questions you may have about the legal use of images, videos, text, etc.
DPMI - Dos Protected Mode Interface - according to the standard: "The DOS Protected Mode Interface (DPMI) was defined to allow DOS programs to access the extended memory of PC architecture computers while maintaining system protection. DPMI defines a specific subset of DOS and BIOS calls that can be made by protected mode DOS programs. It also defines a new interface via software interrupt 31h that protected mode programs use to allocate memory, modify descriptors, call real mode software, etc."
DNS - Domain Name Service - this is how you can find a machine on the Internet (a fuller discussion involves a large book.) If you're really serious about learning this stuff, go to the BIND home page. Or you can visit SamSpade.org for a bit friendlier discussion.
domain - on an NT network, a group of computers that are administered as a single unit with controls for accounts, groups, login scripts and access rights to network resources. On the Internet, it refers to the name an entity has chosen to identify themselves to other nodes. Essentially, a domain name is an "address" which uniquely identifies a network to all other networks.
DOS - Disk Operating System - there's lots of different versions of DOS. MS-DOS is the most widely used.
DoS - Denial of Service - an attack against a host to render it unusable.
download - to move or copy data, files or programs from a remote site to your computer.
DSL - Digital Subscriber Line - there are many variations of this being developed; ADSL, VHDSL, iDSL, etc.
DSLAM - Digital Subscriber Line Access Multiplexor - the box that combines a group of DSL lines together at the CO and connects them to an access provider.
DUL - Dial Up List - a list of dialups known to be used by spammers. Networks can use the list to automatically block all mail from those dialups. This is one of the services that MAPS offers.
DVD - Digital Versatile Disk (sometimes called Digital Video Disk) - a large capacity storage device that may obsolete the CD ROM.
DVD ROM - Digital Versatile Disk, Read Only Memory - just like the CD ROM, once it's stamped by the vendor, it cannot be overwritten. Typically, they hold almost 5GB, which is almost eight times as much data as a CD ROM!

EAP - Extensible Authentication Protocol - an extension to PPP. EAP is a general protocol for authentication that also supports multiple authentication methods, such as token cards, Kerberos, one-time passwords, certificates, public key authentication and smart cards. IEEE 802.1x specifies how EAP should be encapsulated in LAN frames. In wireless communications using EAP, a user requests connection to a WLAN through an AP, which then requests the identity of the user and transmits that identity to an authentication server such as RADIUS. The server asks the AP for proof of identity, which the AP gets from the user and then sends back to the server to complete the authentication. EAP is defined by RFC 2284.
EBCDIC - Extended Binary-Coded Decimal Interchange Code - (pronounced ep-seh-dic) - used in IBM mainframes to represent characters as numbers. Similar to the way ASCII works on PCs.
emulator - a program that imitates (emulates) another program or device. For example, the TCP3270 emulator we use to access the mainframe imitates an IBM terminal.
ERP - Enterprise Resource Planning - a new buzz word in higher education. It refers to using software which interacts with a relational database system to manage the various processes of an entity in a way that increase efficiency and reduces cost.
ethernet - a LAN protocol developed by Xerox and DEC (Digital Equipment Corporation) that allows data transfer rates of 10Mb; often called 10Base-T, 10Base-2 or 10Base-5. (The differences designate the type of cable used; T = twisted pair/RJ45, 2 and 5 are types of coaxial cable - 2 is commonly called Thinnet - 5 is commonly called Thicknet.)
exabyte - 10¹⁸ bytes. 1,000,000,000,000,000,000 bytes. 1000 petabytes. See the NIST page for details.
exbibyte - 2⁶⁰ bytes. 1,152,921,504,606,846,976 bytes. 1024 pebibytes.

FAQ - Frequently Asked Questions - a compendium of the most frequently asked questions, intended to lessen repetitive questions on a particular topic. Go to faqs.org to find them.
FAT - File Allocation Table - a table that contains the location of files on a disk. Used by DOS. Later versions of Windows 95 use FAT32, which is a newer version of FAT. (So does Windows 98.)
fast ethernet - a newer version of Ethernet that allows data transfer rates of 100MB on a LAN - also called 100Base-T.
Firewire - a new technology that allows a computer to have an almost unlimited number of devices running without using up all the hardware interrupts. Developed by Apple, MACs were the first to use Firewire in production models.
FQDN - Fully Qualified Domain Name - the complete name of a host on a network, including the network's name and the top level domain (TLD.) For example, the host "apache" resides in the "utdallas" domain, which is part of the "edu" TLD, so the FQDN of apache is "apache.utdallas.edu". If you cannot resolve (i.e. locate) hosts from your machine, the Domain Suffix Search order (in our case, utdallas.edu)is incorrectly configured on your machine. That is why you have to use the FQDN to locate a host on the same network.
Fresnel Zone - (pronounced 'fre-nel' the "s" is silent) The area around the visual line-of-sight that radio waves spread out into after they leave the antenna. This area must be clear or else signal strength will weaken. Fresnel Zone is an area of concern for 2.4 GHz wireless systems. Although 2.4 GHz signals pass rather well through walls, they have a tough time passing through trees. The main difference is the water content in each. Walls are very dry: trees contain high levels of moisture. Radio waves in the 2.4 GHz band absorb into water quite well. This is why microwaves -- which also use the 2.4GHz band -- cook food. Water absorbs the waves, and heat from the energy cooks the food.
FTP - File Transfer Protocol - the protocol used for moving and copying files on the Internet. It can be used both for downloads and uploads.

gateway - the link between two subnets or networks. We usually use 100 as the gateway address (i.e. 129.110.27.100 is the gateway for subnet 27.)
GB - gigabytes - 10⁹ bytes. 1,000,000,000 bytes. 1000 megabytes. See the NIST page for details.
Gbs - gigabits per second. 10⁹ bits per second.
GiB - (also gib) gibibyte - 2³⁰ power - bytes. 1,073,741, 824 bytes. 1024 mebibytes.
gigabit ethernet - a newer version of Ethernet that allows data transfer rates of 1Gbs. Note that network data transfer rates are measured in bits per second, not bytes.
GNU - Gnu's Not Unix - a UNIX compatible software system which distributes software free of charge.
GPL - General Public License - the GNU license, which allows people to charge for distribution of the software, but not for the software itself.
GPRS - General Packet Radio Service - a standard for wireless communications which runs at speeds up to 115 kilobits per second, compared with current GSM (Global System for Mobile Communications) systems' 9.6 kilobits. GPRS, which supports a wide range of bandwidths, is an efficient use of limited bandwidth and is particularly suited for sending and receiving small bursts of data, such as e-mail and Web browsing, as well as large volumes of data.
GSM - Global System for Mobile Communications - one of the leading digital cellular systems. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency. GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the de facto standard in Europe and Asia.
GUI - Graphical User Interface - first developed by Xerox, and used in the Apple computer, this is the pictorial presentation screen commonly used in computers today (instead of text only) that allows people to use computers without knowing the underlying command language.

hardware - the physical devices that make up a computer. Hard drives, floppy drives, CD ROM drives, etc.
HLLAPI - High Level Language Application Programming Interface - used with IBM mainframes to allow PC's to communicate with the mainframe using an emulator. (In our case, the emulator is TCP3270.)
host - a term for a remote computer that is accessed by a terminal program, such as telnet.
HSRP - Hot Standby Routing Protocol - provides automatic router backup when using a Cisco router. It allows a router to assume the duties of another router when the second router fails.
HTML - Hyper Text Markup Language - the code that makes web pages work.
HTTP - Hyper Text Transfer Protocol - that's how you get to see web pages. HTTP defines how pages should be formatted and what commands they should recognize.
hub - a device used to supply a data connection to more than one machine from a single incoming data port. These are usually used to supply multiple machines on a subnet from a central wiring location.

IAB - Internet Architecture Board - the advisory group which oversees the functions of the IETF and the IESG, oversees the Internet Standards process and publishes and maintains the RFCs. A part of the Internet Society.
IANA - Internet Assigned Numbers Authority - they manage IP address space, root nameservers and domain names among other things. They're being replaced by ICANN.
ICANN - Internet Corporation for Assigned Names and Numbers - the successor to IANA.
ICMP - Internet Control Message Protocol - the protocol for ping and some housekeeping chores for IP.
IDE - Integrated Drive Electronics (or Intelligent Drive Electronics) - the most commonly used interface for hard drives in personal computers. Also stands for Integrated Development Environment - a programming environment built in to an application.
IETF - Internet Engineering Task Force - the primary standards organization for the Internet. It is made up of volunteers who have an interest in the workings of the Internet.
IESG - Internet Engineering Steering Group - along with the IAB, they "organize and manage" the Standards process.
IIS - Internet Information Server® - Microsoft's version of a web server.
IKE - Internet Key Exchange - the standard for negotiating VPN sessions and managing encryption keys that are used in VPN sessions.
IMAP4 - Internet Message Access Protocol, Version 4 - an email protocol that allows you to view mail in folders, keep mail on the server to read in multiple locations and maintain a consistent appearance in every location. Each location's client will synchronize with the server.
IMC - Internet Mail Consortium - according to their web site "an international organization focused on cooperatively managing and promoting the rapidly-expanding world of electronic mail on the Internet".
ini - ini is a file extension, which refers to files used by Windows to determine configuration information for applications. In many cases, ini files have been replaced by the Windows Registry, a configuration database used by Windows 95/98 and NT.
internet - a global, distributed network. Internet is short for Interconnected Networks. The Internet is a cooperative network where individual LANs agree to connect to each other, either directly or through intermediaries for the purpose of sharing data.
Internic - the domain registry service for .com, .net and .org.
interrupt - a signal indicating to a program that some event has occurred. On PCs, there are only 15 hardware interrupts available. This limits the number of devices which can be added to a PC.
intranet - a new term used to describe the Internet-like services (Web pages, etc.) which are only available inside a LAN and cannot be seen by the computers on the Internet.
IP address - Internet Protocol address - a numerical representation of a machine on a network. Each machine has a unique IP address. At UTD, the first two octets of an IP address represent our domain (129.110.) The third octet represents the subnet, and the fourth octet represents a particular machine. So a machine with the address 129.110.159.12 would be located at UTD (129.110) on subnet 159, machine number 12. IP addresses are to computers what your mailing address is to you. They positively locate a machine.
IPSec - IP Security - a set of protocols that allow the secure exchange of information using IP packets.
IPX/SPX - Internetwork Packet Exchange/Sequenced Packet Exchange - a protocol used in Novell networks and lots of networked computer games. In functions in a similar manner to TCP/IP.
IR - Information Resources - the department at UTD which bears responsibility for all computing on campus not directly owned by a department. This includes mainframe, UNIX and desktop systems, as well as all backbone and infrastructure issues, telecommunications, technical support and student computer labs. The Executive Director is Mr. William Hargrove.
IRQ - an abbreviation of Interrupt ReQuest line - a hardware line over which devices can send interrupt signals to the CPU. (It's how your CD ROM gets your computer's attention.)
IRTF - Internet Research Task Force - a group focused on researching Internet protocols, applications, architecture and technology
ISC - Internet Software Consortium - "a nonprofit corporation dedicated to production-quality software engineering for key Internet standards."
ISDN - Integrated Services Digital Network - faster than a modem, slower than ADSL and cable modems.
ISOC - Internet SOCiety - from their web page: "Since 1992, the Internet Society has served as the international organization for global coordination and cooperation on the Internet, promoting and maintaining a broad spectrum of activities focused on the Internet's development, availability, and associated technologies."
ISP - Internet Service Provider - a commercial enterprise that offers connections to the internet for a monthly fee or some other type of remuneration (like advertising.)
ITLA - Incremented Three Letter Acronym - believe it or not, at one time IBM ran out of TLAs. In order to move to four letter acronyms, they had to come up with a four letter acronym to replace TLA. But FLA wouldn't work, because that was only three letters. So ITLA was adopted as the "standard" to describe all four letter acronyms! True story!

Java - a programming language invented by Sun Microsystems. It is a cross platform language used extensively in embedded systems (such as coffee makers, timers used in manufacturing, etc.) and on the Internet to create animated effects on web sites.
JavaBean - objects that conform to a Sun Microsystems specification that defines how Java objects should interact. Similar to ActiveX controls, except they can only be written in Java, but will run on any platform.
Javascript - a scripting language invented by Netscape Communications Corporation. Used extensively on the Internet for numerous functions on web pages, such as clocks, browser detection, warning popups, page redirection, etc.
JFK - Just Fast Keying - a simple protocol for establishing VPN sessions

KB - kilobyte - 10³ bytes. 1000 bytes. See the NIST page for details.
Kbs - kilobits per second - 10³ - bits per second. 1000 bits per second. Note that network data transfer rates are measured in bits per second, not bytes.
KiB - kibibyte - 2¹⁰ bytes. 1024 bytes.

LAN - Local Area Network - what UTD's network is.
LDAP - Lightweight Directory Access Protocol - a set of protocols for accessing directories of information such as email addresses and public keys.
LEC - Local Exchange Carrier - Southwestern Bell and GTE in the DFW area.
Linux - a UNIX OS created by Linus Torvald - runs on the same kind of computers as Windows (as well as many other kinds of computers.) Linux a unique UNIX OS which has been developed entirely by volunteers and is available for free. Some others are FreeBSD and NetBSD.
LMDS - Local Multipoint Distribution Services - a fixed (non-mobile) wireless technology that operates in the 28 GHz band and offers line-of-sight coverage over distances up to 3-5 kilometers. It can deliver data and telephony services to 80,000 customers from a single node. LMDS is one solution for bringing high-bandwidth services to homes and offices within the "last mile" of connectivity, an area where cable or optical fiber may not be convenient or economical. Data transfer rates for LMDS can reach 1.5 Gbps to 2 Gbps, but a more realistic value may average around 38 Mbps (downstream).

MAC - Media Access Control - (also short for Macintosh) - a hardware address that uniquely identifies each node on a network. We ask you for this when you want to get an IP address.
MAE - Metropolitan Area Ethernet - a NAP where ISPs can interconnect. They are all owned by MCI Worldcom. The first was in Washinton, D.C., called MAE EAST, followed by one in San Jose, California, called MAE WEST. Now there are seven, including MAE DALLAS, MAE CHICAGO, MAE HOUSTON, MAE NEW YORK and MAE LOS ANGELES. Two new MAEs are being added, MAE PARIS in Paris, France and MAE FRANKFURT in Frankfurt, Germany.
MAPS - Mail Abuse Protection System - an organization that provides information to networks about other networks that are tolerating email abuse. They provide several lists which networks can use to block mail coming from abusive sites.
MB - (also Meg) Megabyte - 10⁶ bytes. 1,000,000 bytes. 1000 kilobytes. See the NIST page for details.
Mbs - megabits per second - 10⁶ bits per second. 1,000,000 bits per second. 1000 kilobits per second. Note that network data transfer rates are measured in bits per second, not bytes.
MiB - mebibyte - 2²⁰ bytes. 1,048,576 bytes. 1024 kibibytes.
MIB - Management Information Base - a database of objects managed by a network management system, such as SNMP.
MILNET - Military Network - see the MILNET web site for details.
MIME - Multipurpose Internet Mail Extensions - a specification that allows files such as movies, audio and pictures to be sent over the Internet in an email message.
MIPS - Million Instructions Per Second - the MIPS rating of a CPU tells you how fast it is.
MITM - Man In The Middle - a type of network attack where the intruder intercepts traffic between two hosts and answers each one, fooling the hosts into thinking they are talking directly to each other.
MODEM - Modulator/Demodulator - a device that allows computers to transfer data over ordinary telephone lines.
motherboard - the main circuit board of a computer. It contains the CPU, memory, ports and controllers for the peripherals.
MTA - Mail Transfer Agent. The server that handles email.
MUA - Mail User Agent - the client that you read your email with. Common ones are Netscape, Eudora, Outlook Express, Pine, Mulberry and Simeon.

NANOG - The North American Network Operators Group - NANOG "provides a forum for the exchange of technical information, and promotes discussion of implementation issues that require community cooperation. Coordination among network service providers helps ensure the stability of overall service to network users."
NAP - Network Access Point - a major access point on the Internet. There are several - BIG EAST operated by ICS Systems, the Chicago NAP operated by Ameritech, the New York NAP operated by Sprint, the San Francisco NAP operated by PacBell and the Washington NAP (also known as MAE EAST) operated by MCI Worldcom.
s NAT - Network Address Translation - a protocol that allows the use of "private" IP addresses (10.0.0.0, 172.16.0.0 and 192.168.0.0) that are not routed across the Internet, to access the Internet. On the "inside" of the network, private IP addresses are used, and NAT allows those machines to access the Internet by "translating" their private IP to a public, routeable IP address. NAT users cannot accept connections from public machines, so this prevents the use of "Internet-facing" servers, some forms of FTP, certain types of file sharing, and similar type activities.
NetBEUI - NetBIOS Enhanced User Interface - an enhanced version of NetBIOS used only on Windows networks. NetBEUI will not cross subnets, so it's useless on a LAN like UTD has. It's also very "chatty", which is a geek's way of saying it uses broadcast traffic rather than talking to only the machine it wants to talk to. Chatty protocols tend to fill up the network making it run slower, which is a real concern for a large network such as ours.
NetBIOS - Network Basic Input/Output System - the network API which is used for all Windows networks. This is what allows you to "see" other Windows PCs in Network Neighborhood.
NIC - Network Interface Card - the peripheral that connects your computer to the LAN. It has a unique MAC address, which ARP converts to an IP address so that your machine can communicate with other hosts using TCP/IP.
NNTP - Network News Transport Protocol - hopefully you'll be using this one soon. :-)
node - in networks, a computer or other processing device. On the Internet, a network connected to the Internet.
NSF - National Science Foundation - the coordinating entity behind the beginnings of the present day Internet. They built NSFnet, which replaced ARPANET. NSFnet was dismantled and replaced by a commercial Internet in 1995. Now the NSF is working on the new vBNS Internet.
NSFnet - the network the NSF built in 1987 to replace in ARPANET.
NSLookup - Name Server Lookup - a utility for converting IP addresses to the associated hostname and vice versa.
NSP - Network Service Provider - these are the large companies that supply ISPs with their connection to the Internet. Folks like Sprint, AT&T, WorldCom, UUNET, BBNPlanet, etc.
NTFS - NT File System - the file system used by NT. NT also supports FAT for "backwards compatibility".
NTP - News Time Protocol - allows you to synchronize your computer's clock with a time standard like the US Naval Observatory.

OCR - Optical Character Recognition - this is a technology that allows computers to "read" text and convert it to an image that can be viewed.
ODBC - Open DataBase Connectivity - a standard database accessing method developed by Microsoft .
OEM - Original Equipment Manufacturer
OGC - Office of General Counsel - the legal division of UT System.
ORBS - Open Relay Behaviour-modification System - a list of open relays that are used by spammers - networks can use this list to block mail from those sites - see the ORBS web site for details.
OS - Operating System - the program that performs the basic tasks of a computer, such as keyboard input, mouse movement, file management, control of peripherals and displaying information on the screen. It underlies the applications you use to do work (like word processors, spreadsheets, databases, etc.)
OSPF - Open Shortest Path First - a routing protocol that allows routers to interact to determine the shortest path between two points.

packet - a part of a message on a network. Along with the data being sent, it contains both the originating and destination addresses.
PB - petabyte - 10¹⁵ bytes. 1,000,000,000,000,000 bytes. 1000 terabytes. See the NIST page for details.
PCI - Peripheral Component Interconnect - the newest technology for data transfer on the motherboard.
PCM - Pulse Code Modulation - the method of achieving the connection speed of 56K modems.
PCMCIA - Personal Computer Memory Card International Association - this is the standard for those little plug-in cards used in laptop computers - like PCMCIA Modems and PCMCIA NICs.
PDA - Personal Digital Assistant - a class of electronic devices that are small enough to be handheld and fit in a shirt pocket or purse. E.g. Palm devices, IPAQs, Handspring Visors, etc.
PDC - Primary Domain Controller - in an NT domain, the PDC is authoritative for all accounts, groups, permissions and login scripts. All the BDCs synchronize their databases with the PDC.
PDF - Portable Document Format - you need Adobe Acrobat to view these. It allows you to view documents regardless of the OS you are using.
peripherals - external devices which can be attached to computers, like printers, scanners, mice, keyboards and storage devices.
PERL - an interpreted programming language. Created by Larry Wall, PERL is used for CGI scripting on web pages, which allows us (among other things) to accept information you put in the Problem Reporting Form and send mail to assist with all that information properly formatted while showing you a web page that says "Thank you for your input".
PiB - pebibyte - 2⁵⁰ bytes. 1,125,899,906,842,624 bytes. 1024 tebibytes.
PING - Packet INternetwork Groper - a utility used to determine if a host is "alive". It sends an ICMP echo message and reports whether the message was returned and the time it took to return.
PKI - Public Key Infrastructure - a system of keys, digital certificates and certifying authorities that ensure an individual involved in an Internet transaction is who they claim to be. UT System will be adopted such a system in the near future, and all System email will have to be digitally signed.
plug-in - a programmed module designed to work as part of a larger system and provide additional functionality, such as Shockwave®, which allows a web browser to display animated movies and other special effects.
POP3 - Post Office Protocol, Version 3 - a method of retrieving email from a mail server which is used extensively on the Internet.
POST - Power On Self Test - the first thing an Intel-based machine does when you turn it on. If the system has a problem, a series of beeps will indicate what the problem is (sometimes.)
POTS - Plain Old Telephone Service - seriously!
PPP - Point to Point Protocol - a method of connecting to the Internet that allows you to see web pages, read newsgroups & send mail (among other things.)
PPTP - Point To Point Tunneling Protocol - a protocol that allows you to exchange data over the Internet in a secure manner.
PROM - Programmable Read Only Memory - a special kind of ROM which can be programmed once.
protocol - specific format for transmitting data between two devices. It defines how the sending device will indicate it has transmitted the data, how the receiving device will indicate it has received it and what error checking will be done to ensure accuracy.

queue - a part of the hard drive or memory the computer sets aside for temporary storage while it waits for some other device to indicate it is ready to accept the data, like a print queue where print jobs are "stored" until the printer is ready to accept them

RADIUS - Remote Authentication Dial-in User Service - by far the most common method on the Internet for authenticating remote users.
RAM - Random Access Memory - memory which can be "written to" over and over again. Computers use this to store data for use during normal operations. Sometimes called "main memory", which is a reference to its extensive use in computing. It is erased whenever the power is turned off.
RAT - Remote Administration Tool - refers to products such as PC Anywhere and Carbon Copy but is more often used to refer to trojan RATs such as Back Orifice and NetBus.
RBL - Realtime Blackhole List - a part of the MAPS project - used to block mail from networks that seem unable to prevent spam from emanating from their network.
RBOC - Regional Bell Operating Company - the regional Bell systems which were created by the court ordered breakup of AT&T.
registry - a special database used by Windows 95, 98 and NT to store configuration information, personal preferences, user information, hardware settings and file associations for use by programs and the OS.
RDBMS - Relational DataBase Management System - a type of database that stores data in related tables. A powerful form of database due to its flexibility.
RDRAM - Rambus Dynamic Random Access Memory - newer and faster memory
RFC - Request For Comments - the standards for Internet operation - you can find them at the RFC Editor site. You can also find them at faqs.org. Some of them are standards, others are informational. Some are proposals for new standards.
RFD - Request For Discussion - this is how new newsgroups are proposed. You can find a good explanation of the process with links to the proper locations here.
RIP - Routing Information Protocol - a routing protocol that uses hop counts to determine paths within a single autonomous network.
RIPE - Réseaux IP Européens - the Internet registry organization for Europe.
RNA - Remote Network Access - the new dialup system UTD has implemented. For details, you may visit the RNA page.
ROM - Read Only Memory - memory that is written to only once. It is usually used to store data that is needed for routine operations, such as the ROM that boots your computer. ROM is used extensively in calculators and other hand-held devices. It retains its data when the power is turned off.
router - a device that connects two or more subnets or networks together. Routers have tables with MAC addresses in them that point to the location of a particular node on the network. They are like the information center where computers can go to find out where another computer is located.

safe mode - a special boot process used for troubleshooting Windows 95/98 that only loads essential drivers to bring up the GUI.
SCSI - Small Computer System Interface - the most commonly used hard drive interface in servers and UNIX and MAC (until recently) computers - faster and more reliable than IDE.
SDRAM - Synchronous Dynamic Random Access Memory
server - a special computer used to provide access to files, databases, or printers or to control network traffic or access rights.
shares - a term that refers to sections of a hard drive on an NT server that are accessed by one or more users. (Your home directory, for example, is a "hidden" share. You can't see it by looking in Network Neighborhood. You have to know what its name is to find it.)
SMTP - Simple Mail Transport Protocol - the protocol that is used to send email between servers. You then use a client with POP3 or IMAP4 to read/retrieve your email. This is why you have to specify two different servers in your email client; smtp.utdallas.edu and inbox-?.utdallas.edu (where the ? is replaced by the first initial of your username.)
SNA - Systems Network Architecture - a set of protocols used by IBM to interconnect hosts.
SNMP - Sorry, Not My Problem - just kidding! Simple Network Management Protocol - a set of protocols used to manage complex networks.)
software - the programs that enable a computer to perform tasks
social engineering - The use of techniques that will fool a user into divulging important information or the theft of useful information by going through the trash. Some examples are: calling a user posing as a network engineer and asking for their password so they can "check the account"; digging through the trash and finding a password written on a piece of paper; using email to pose as a service provider and asking for username and password before you can view a web site or get logged on (this is a VERY common method of stealing AOL accounts); calling a user posing as an authority figure and convincing them that their account has been compromised. Then stating that they "just need to verify your account information" and asking for the username and password.
spam - unsolicited email, the use of the term comes from a Monty Python skit where a group began chanting "spam, spam, spam, spam", drowning out all conversation.
subnet - a small part of a network where all the machines share a common address. At UTD, the subnets are the third part of the IP address.
subnetmask - a special numerical formula that defines to a computer or router what constitutes a subnet. We use 255.255.255.0, which tells the computer or router that the third octet represents a subnet address. The math that accomplishes this is fascinating. If you're interested, CISCO has technical documentation that explains the process.

TASSCC - Texas Association of State Systems for Computing and Communications - a Texas association dedicated to "advancing cooperation, innovation, education, excellence and sound public policy in the application of information and communication technology to the provision of public service.
TB - terabyte - 10¹² bytes. 1,000,000,000,000 bytes. 1000 gigabytes. See the NIST page for details.
TCP/IP - Transmission Control Protocol/Internet Protocol - the reason the Internet works. TCP/IP is a protocol that allows data to be transmitted in packets without regard to whether or not they are received correctly. If the receiving machine doesn't get the packet intact, it simply requests that it be resent.
TCS - Technology Customer Services - the division of UTD IR responsible for technical support of all desktop systems and software, the Help Desk, PC LAN servers and infrastructure, PC systems programming, student computer labs and campus computer training. The director is Mr. Douglas Jackson.
telnet - a terminal emulation program used to access UNIX systems from a remote location. It allows you to run programs as if you were sitting at the server keyboard.
TDMA - Time Division Multiple Access - a technology for delivering digital wireless service using time-division multiplexing (TDM). TDMA works by dividing a radio frequency into time slots and then allocating slots to multiple calls. In this way, a single frequency can support multiple, simultaneous data channels. TDMA is used by the GSM digital cellular system.
TiB - tebibyte - 2⁴⁰ bytes. 1,099,511,627,776 bytes. 1024 gibibytes.
TLA - Three Letter Acronym - really!
TLD - Top Level Domain - in our case .edu - in the case of a country .se or .uk or .au etc. If you're interested in such things, you can find a list of all the country domains at IANA.
traceroute - a utility used to trace the route from one host to another. It reports the time it takes for each host in the path to respond to a UDP message to an invalid port address as well as the hostname of the devices the signal travels through. The Windows version is tracert. (Still adhering to that old 8 character limitation from DOS for some reason.)
Trojan Horse - not Homer's....this refers to programs sent to unsuspecting users disguised as something they are not. Generally, they are used to install software that allows the attacker to control the machine without the user's knowledge or to gather information about the victim's machine and network.
TWAIN - Toolkit Without An Interesting Name - seriously! TWAIN makes it easier for programs to work with OCR software.

UI - User Interface - a term that describes the interface you use to interact with a computer.
UDP - User Datagram Protocol - a connectionless protocol used on the Internet. Used primarily for broadcast traffic where a response is not necessarily required.
UltraDMA - Ultra Direct Memory Access - better than just DMA, of course.
UMS - University Management Systems - the division of UTD IR responsible for all mainframe computing including financial, student and human resources records, Touch Tone® Registration Services, numerous specialized applications that access the mainframe databases and programming services related to the mainframe. The Director is Mrs. Barbara Toney.
UNC - Universal Naming Convention - the PC format for specifying the location of servers, directories and files. For example \\servername\directoryname\filename.
UNIX - a popular OS developed by AT&T at the Bell Labs in the early '70s. There are many different types of UNIX now, including NetBSD, FreeBSD, SunOS, Solaris, SysV, SVR4, XENIX, ULTRIX, HP-UX, Dec UNIX, AIX, SCO UNIX, LINUX, etc. UNIX is the OS of the Internet.
upload - to move or copy data, files or programs from your computer to a remote location, such as your web page directory on UNIX.
URL - Uniform Resource Locator - the "address" system of the Internet.
USB - Universal Serial Bus - a fairly new technology that allows more than one peripheral to share the same interrupt. This increases the number of peripherals that can be added to a personal computer.

VAX Virtual Address eXtension - a type of Digital Equipment Corporation minicomputer. It ran the VMS operation system.
vBNS very high-speed Backbone Network Service. The next generation Internet. Sponsored by the NSF and implemented by MCI, vBNS presently supports data transfer rates of 622Mbs and is expected to eventually support 2.5Gbs speeds.
VGA - Video Graphics Array - the de facto standard for graphics display in PCs.
virus - A virus is a program that can replicate itself by infecting certain types of files (.com, .exe, .doc, .xls, etc.) The program code is actually inserted into an existing file which changes the size of the file by the size of the viral code. (In some cases, the virus actually takes advantage of "empty space" in a file so that it does not appear to have changed the file at all.) Once the code has been inserted into a file, if that file is run, the code will then insert itself into many other files of the same type. Infected files must be deliberately shared (intentionally or unintentionally) with other people in order to spread to other machines.
VLAN - Virtual LAN - the latest thing in LANs. It's a complex subject to the layman, but if you're interested and you've got a lot of time on your hands, you can learn more from 3COM's "White Paper" on Layer 3 Switching.
VMS - an operating system that ran on the VAX minicomputer made by Digital Equipment Corporation (DEC.) It was a multi-user, multi-tasking Virtual Memory operating System, thus the acronym, VMS.
VPN - Virtual Private Network - a term for a number of technologies that allow you to exchange data securely over the Internet. PPTP is a subset of VPN.
VRAM - Video Random Access Memory - a special type of RAM that can be accessed by two devices at once. This allows for much faster "painting" of graphics on the display device.
VRML - Virtual Reality Modeling Language - a new language used on web pages to create all sorts of special effects.
VSAM - Virtual Storage Access Method - an IBM mainframe file management system.
VTAM - Virtual Telecommunications Access Method - IBM software which allows for communication in SNA networks, the IBM network structure.

WAN - Wide Area Network - two or more LANS in different geographical locations connected together over phone lines.
WEP - Wired Equivalent Privacy - a security protocol for wireless local area networks (WLANs) defined in the 802.11b standard. WEP is designed to provide the same level of security as that of a wired LAN. LANs are inherently more secure than WLANs because LANs are somewhat protected by the physicalities of their structure, having some or all part of the network inside a building that can be protected from unauthorized access. WLANs, which are over radio waves, do not have the same physical structure and therefore are more vulnerable to tampering. WEP aims to provide security by encrypting data over radio waves so that it is protected as it is transmitted from one end point to another. However, it has been found that WEP is not as secure as once believed. WEP is used at the two lowest layers of the OSI model - the data link and physical layers; it therefore does not offer end-to-end security.
WECA - Wireless Ethernet Compatibility Alliance - an organization made up of leading wireless equipment and software providers with the mission of guaranteeing interoperability of Wi-Fi products and to promote Wi-Fi as the global wireless LAN standard across all markets.
WiFi - Wi reless Fi delity - another name for IEEE 802.11b. It is a trade term promulgated by the Wireless Ethernet Compatibility Alliance (WECA). "Wi-Fi" is used in place of 802.11b in the same way that "Ethernet" is used in place of IEEE 802.3. Products certified as Wi-Fi by WECA are interoperable with each other even if they are from different manufacturers. A user with a Wi-Fi product can use any brand of access point with any other brand of client hardware that is built to the Wi-Fi standard.
WiFi5 - Refers to wireless LAN products based on the IEEE 802.11a specification that operate in the 5 GHz radio frequency band. Only products that have passed WECA's interoperability testing are allowed to display the Wi-Fi5 certification logo.
WINS - Windows Internet Naming Service - a Windows service which relates Windows NetBIOS names to IP addresses.
WIPO - World Intellectual Properties Organization - an UN organization, based in Geneva, Switzerland, formed for the purpose of promoting the protection of intellectual property copyrights worldwide through treaty agreements between all participating countries.
worm - A worm is a program that can replicate itself by using the capabilities of an operating system or one or more of its components to recreate itself on other systems. Worms do not infect files like viruses do, but they can replace files with "infected" copies. Worms can spread through a network without users sharing files.
WYSIWYG - What You See Is What You Get - pronounced wiz-ee-wig - refers to software that is supposed to display the actual web page in the same window you edit the web page from - like Microsoft's FrontPage® web page editor.

XML - eXtensible Markup Language - an Internet standard that allows content authors to design their own markup tags. This allows a much broader use of material in "legacy" format to be displayed on the web without extensive modifications
XMS - Extended Memory Specification - a procedure used to access "high" memory in DOS.
XSLT - eXtensible Style Language Transformation - the language used in XSL style sheets to "interpret" XML coding and display it in a language the viewer will understand.

Y2K - Year 2000 - you know what that means by now, don't you?
yottabyte - 2 to the 80th power - bytes. 1,208,925,819,614,629,174,706,176 bytes. 1024 zettabytes.

zettabyte - 2 to the 70th power - bytes. 1,180,591,620,717,411,303,424 bytes. 1024 exabytes.
ZIP drive - a large capacity floppy disc drive developed by IOMEGA Corporation. Used for backing up important data.