Return to List of Terms

UART
Universal Asynchronous Receiver/Transmitter, is a computer component that handles asynchronous serial communication. Every computer contains a UART to manage the serial ports. As modems have become increasingly fast, the UART has come under greater scrutiny as the cause of transmission bottlenecks, therefore make sure your PC has a 16550 UART if you have a fast external modem.

UDDI
Universal Description, Discovery and Integration. A Web-based distributed directory that enables business to list themselves on the Internet and discover each other, similar to a traditional phone book's yellow and white pages.

UDP
User Datagram Protocol, a connectionless protocol that, like TCP, runs on top of IP networks. Unlike TCP/IP, UDP/IP provides very few error recovery services, offering instead a direct way to send and receive datagrams over an IP network. It's used primarily for broadcasting messages over a network.

UML
Unified Modeling Language, a general-purpose notational language for specifying and visualising complex software, especially large, object-oriented projects.

UMTS
Universal Mobile Telecommunications System.

UNC
Universal Naming Convention or Uniform Naming Convention, a PC format for specifying the location of resources on a LAN. UNC uses the following format: \\server-name\shared-resource-pathname So, for example, to access the file test.txt in the directory etc on the shared server gray, you would write: \\gray\etc\test.txt
You can also use UNC to identify shared peripheral devices, such as printers. The idea behind UNC is to provide a format so that each shared resource can be identified with a unique address. UNC is supported by Windows and many network operating systems (NOS's).

Unicode
Standard character set compatible with many languages.

UNIX
A multi-user, multi-tasking, operating system developed in the 70's. It was able to run on any computer that had a C compiler. It is still very much used by today's web developers.

Uploading
Transfering files to the Internet  or network so to be accessed via a web browser.

URI
Uniform Resource Identifier.

URL
Universal Resource Locator - most commonly seen in the form of a web page address, but can point to any usable resource on the internet, e.g. graphics files and other media.

USB
Universal Serial Bus, is an external bus standard that supports data transfer rates of 480Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play installation and hot plugging.
Starting in 1996, a few computer manufacturers started including USB support in their new machines. It wasn't until the release of the best-selling iMac in 1998 that USB became widespread. It is expected to completely replace serial and parallel ports.

USENET
A Bulletin Board system where each collection of posted notes is known as a newsgroup.

USSD
Unstructured Supplementary Service Data, is a GSM communication technology that is used to send text between a mobile phone and an application program in the network. USSD is similar to Short Messaging Service, but, unlike SMS, USSD transactions occur during the session only.

UTP
Unshielded Twisted Pair. Copper wiring used in small-to-large networks to connect host devices to hubs and switches.

UUCP
UNIX-to-UNIX Copy Protocol. A method of communicating between different UNIX systems for the copying of files and sending commands to be executed on another system.

UXGA
Ultra Extended Graphics Array, a display specification that is capable of displaying 1600 x 1200 resolution, or approximately 1.9 million pixels.

VAN
Virtual Area Network, is a network which users meet "face to face" and requires broadband.

Vanilla
The basic version of a software or hardware product.

VAX
Virtual Address eXtension, Digital Equipment Corporation's successor to its PDP-11 line of minicomputer. As its name implies, VAX systems feature an operating system, VMS, that supports virtual memory. It was introduced in 1977.

VC
Venture Capitalist. Individual or firm that provides funds for a business because they judge it to have the potential for growth and success.

VCACHE
The disk cache system in Windows 95. VCACHE replaces the Smartdrive system used in older versions of Windows. Whereas SmartDrive is a 16-bit driver, VCACHE is a 32-bit driver. VCACHE can dynamically change the size of the disk cache depending on available disk space and application requirements.

Vector Graphics
Same as OOG, refers to software and hardware that use geometrical formulas to represent images. The other method for representing graphical images is through bit maps, in which the image is composed of a pattern of dots. This is sometimes called raster graphics. Vector-oriented images are more flexible than bit maps because they can be resized and stretched. Another advantage of vector graphics is that representations of images often require less memory than bit-mapped images do. Almost all sophisticated graphics systems, including CADD systems and animation software, use vector graphics.

Veronica
Very Easy Rodent Oriented Netwide Index to Computerised Archives, can be used to find out what is on a Gopher site.

VFAT
Virtual File Allocation Table, a virtual installable files system driver used in Windows for Workgroups and Windows 95.

Video Conferencing
The ability of 2 or more people at different sites to communicate visually by using a network such as the Internet to transmit video.

Virtual Machine
A self-contained operating environment that behaves as if it is a separate computer. For example, Java applets run in a Java virtual machine (VM) that has no access to the host operating system. This design has 2 advantages:

• System Independence: A Java application will run the same in any Java VM, regardless of the hardware and software underlying the system.
• Security: Because the VM has no contact with the operating system, there is little possibility of a Java program damaging other files or applications.

The second advantage, however, has a downside. Because programs running in a VM are separate from the operating system, they cannot take advantage of special operating system features.

Virus
A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across network and bypassing security systems.

VLAN
Virtual LAN, a network of computers that behave as if they are connected to the same wire even though they may actually be physically located on different segments of a LAN. VLANs are configured through software rather than hardware, which makes them extremely flexible. One of the biggest advantages of VLANs is that when a computer is physically moved to another location, it can stay on the same VLAN without any hardware reconfiguration.

VLIW
Very Long Instruction Word, a microprocessor design technology.

VLSM
Variable-Length Subnet Mask. Helps optimise available address space and specify a different subnet mask for the same network number on various subnets.

VMS
Virtual Memory System, a multi-user, multitasking, virtual memory operating system that runs on DEC's VAX and Alpha lines of minicomputer and workstation.

VOD
Video On Demand.

VPN
Virtual Private Network, a network that is constructed by using public wires to connect nodes.

VRAM
Video RAM, is special-purpose memory used by video adapters. Unlike conventional RAM, VRAM can be accessed by two different devices simultaneously. This enables the RAMDAC to access the VRAM for screen updates at the same time that the video processor provides new data. VRAM yields better graphics performance but is more expensive than normal RAM. A special type of VRAM, called Windows RAM (WRAM) , yields even better performance than conventional VRAM.

VRML
Virtual Reality Modelling Language, is a 3-dimensional authoring language.

VRRP
Virtual Router Redundancy Protocol, is an election protocol that dynamically assigns responsibility for one or more virtual routers. See RFC 2338 and RFC 2787

VSAM
Virtual Storage Access Method, a file management system used on IBM mainframes. VSAM speeds up access to data in files by using an inverted index (called a B+tree) of all records added to each file. Many legacy software systems use VSAM to implement database systems (called data sets).

Vulture Capitalist
A predatory venture capitalist or businessman looking to profit from investing in e-commerce.

W3C
World Wide Web Consortium is a group of organisations that exists to develop standards and enhance the WWW.

WAI
Web Accessibility Initiative, an initiative of the World Wide Web Consortium launched in 1997 to ensure that as the Internet grows in usage Web sites are designed to accommodate people with disabilities.

WAIS
Wide Area Information Server, is a system that allows users to retrieve content on the Internet by using natural language searches and indexed searches.

Walled Garden
On the Internet, a walled garden refers to a browsing environment that controls the information and Web sites the user is able to access. This is a popular method used by ISP in order to keep the user navigating only specific areas of the Web, whether for the purpose of shielding users from information -- such as restricting children's access to pornography -- or directing users to paid content that the ISP supports. America Online is a good example of an ISP that places users in a walled garden. Schools are increasingly using the walled garden approach in creating browsing environments in their networks. Students have access to only limited Web sites, and teachers need a password in order to leave the walled garden and browse the Internet in its entirety.
The term walled garden also commonly refers to the content that wireless devices such as mobile phones have access to if the content provided by the wireless carrier is limited.

WAN
Wide Area Network. A network covering a large geographical distance, usually involving computers connected over long-distance communications systems such as telephone lines. May comprise one or more LANs.

WAP
Wireless Application Protocol. Allows users to access parts of the internet via various wireless media such as mobile phones, pagers and two-way radios.

Warchalking
The act of making chalk marks on outdoor surfaces (walls, sidewalks, buildings, sign posts, trees) to indicate the existence of an open wireless network connection, usually offering an Internet connection so that others can benefit from the free wireless access. The open connections typically come from the access points of wireless networks located within buildings to serve enterprises. The chalk symbols indicate the type of access point that is available at that specific spot. There are three basic designs that are currently used: a pair of back-to-back semicircles, which denotes an open node; a closed circle, which denotes a closed node; a closed circle with a “W” inside, which denotes a node equipped with WEP. Warchalkers also draw identifiers above the symbols to indicate the password that can be used to access the node, which can easily be obtained with sniffer software.

WCDMA
Wideband Code-Division Multiple Access, a high-speed 3G mobile wireless technology with the capacity to offer higher data speeds than CDMA. WCDMA can reach speeds of up to 2 Mbps for voice, video, data and image transmission. WCDMA was adopted as a standard by the ITU under the name "IMT-2000 direct spread.".

We-Commerce
A joint e-commerce venture entered into by more than one person.

Web Beacon
Also called a Web bug or a clear GIF. Used in combination with cookies, a Web beacon is an often-transparent graphic image, usually no larger than 1 pixel x 1 pixel, that is placed on a Web site or in an e-mail that is used to monitor the behavior of the user visiting the Web site or sending the e-mail. When the HTML code for the Web beacon points to a site to retrieve the image, at the same time it can pass along information such as the IP address of the computer that retrieved the image, the time the Web beacon was viewed and for how long, the type of browser that retrieved the image and previously set cookie values. Web beacons are typically used by a third-party to monitor the activity of a site. A Web beacon can be detected by viewing the source code of a Web page and looking for any IMG tags that load from a different server than the rest of the site. Turning off the browser's cookies will prevent Web beacons from tracking the user's activity. The Web beacon will still account for an anonymous visit, but the user's unique information will not be recorded.

Web Casting
Using the Internet, and the World Wide Web in particular, to broadcast information. Unlike typical surfing, which relies on a pull method of transferring Web pages, webcasting uses push technologies.

WECA
Wireless Ethernet Compatibility Alliance, an organisation 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.

WEP
Wired Equivalent Privacy, a security protocol for 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.

White Hat
Someone who is paid to hack into computer systems to check the security.

Whitelist
A whitelist is a list of e-mail addresses or domain names from which an e-mail blocking program will allow messages to be received.

wi-fi
wireless fidelity and is another name for IEEE 802.11b. It is a trade term promulgated by WECA. 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.

wi-fi5
Refers to WLAN 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.

WiMAX
WiMAX is a wireless industry coalition whose members organised to advance IEEE 802.16 standards for broadband wireless access networks. WiMAX was formed in 2001.

WINS
Windows Internet Naming Service, a system that determines the IP address associated with a particular network computer. This is called name resolution. WINS supports network client and server computers running Windows and can provide name resolution for other computers with special arrangements. Determining the IP address for a computer is a complex process when DHCP servers assign IP addresses dynamically. For example, it is possible for DHCP to assign a different IP address to a client each time the machine logs on to the network. WINS uses a distributed database that is automatically updated with the names of computers currently available and the IP address assigned to each one. DNS is an alternative system for name resolution suitable for network computers with fixed IP addresses.

WIPO
World Intellectual Property Organisation, is a specialised UN agency formed to protect intellectual property worldwide.

WLAN
Wireless Local Area Network. A type of local-area network that uses high-frequency radio waves rather than wires to communicate between nodes. Also referred to as LAWN.

WML
Wireless Markup Language, an XML language used to specify content and user interface for WAP devices; the WAP forum provides a DTD for WML.

World Wide Web
One of the systems making up the internet. A collection of servers providing documents formatted in HTML known as web pages. The system is normally navigated using a web browser such as Internet Explorer or Netscape Navigator.

Worm
(1) A program or algorithm that replicates itself over a computer network and usually performs malicious actions, such as using up the computer's resources and possibly shutting the system down.

(2) Write Once, Read Many. An optical disk technology that allows you to write data onto a disk just once. After that, the data is permanent and can be read any number of times. WORM is also called CD-R.

WRAM
Windows RAM, a type of RAM developed by Samsung Electronics that supports two ports. This enables a video adapter to fetch the contents of memory for display at the same time that new bytes are being pumped into memory. This results in much faster display than is possible with conventional single-port RAM. WRAM is similar to VRAM, but achieves even faster performance at less cost because it supports addressing of large blocks (windows) of video memory.

WSDL
Web Services Description Language, an XML-formatted language used to describe a Web service's capabilities as collections of communication endpoints capable of exchanging messages. WSDL is an integral part of UDDI, an XML-based worldwide business registry.

WTLS
Wireless Transport Layer Security. WTLS is the security layer of the WAP, providing privacy, data integrity and authentication for WAP services.

WYSIWYG
What You See Is What You Get.

WYSIWYP
What You See Is What You Print, refers to the ability of a computer system to print colours exactly as they appear on a monitor. WYSIWYP printing requires a special program, called a colour management system (CMS) to calibrate the monitor and printer.

xDSL
Refers collectively to all types of Digital Subscriber Lines, the two main categories being ADSL and SDSL. Two other types of xDSL technologies are High-data-rate DSL (HDSL) and Very high DSL (VDSL).
DSL technologies use sophisticated modulation schemes to pack data onto copper wires. They are sometimes referred to as last-mile technologies because they are used only for connections from a telephone switching station to a home or office, not between switching stations.
xDSL is similar to ISDN inasmuch as both operate over existing copper telephone lines (POTS) and both require the short runs to a central telephone office (usually less than 20,000 feet). However, xDSL offers much higher speeds - up to 32 Mbps for downstream traffic, and from 32 Kbps to over 1 Mbps for upstream traffic.

XHTML
Extensible Hypertext Markup Language, a hybrid between HTML and XML specifically designed for Net device displays. XHTML is a markup language written in XML; therefore, it is an XML application. XHTML uses three XML namespaces (used to qualify element and attributes names by associating them with namespaces identified by URI references. Namespaces prevent identically custom-named tags that may be used in different XML documents from being read the same way), which correspond to three HTML 4.0 DTDs: Strict, Transitional, and Frameset. XHTML markup must conform to the markup standards defined in a HTML DTD. When applied to Net devices, XHTML must go through a modularization process. This enables XHTML pages to be read by many different platforms. A device designer, using standard building blocks, will specify which elements are supported. Content creators will then target these building blocks--or modules. Because these modules conform to certain standards, XHTML's extensibility ensures that layout and presentation stay true-to-form over any platform.

XLink
XML Linking Language.

XML
Short for Extensible Markup Language, a specification developed by the W3C. XML is a pared-down version of SGML, designed especially for Web documents. It allows designers to create their own customized tags, enabling the definition, transmission, validation, and interpretation of data between applications and between organizations.
Whether XML eventually supplants HTML as the standard Web formatting specification depends a lot on whether it is supported by future Web browsers. Microsoft Internet Explorer version 5 handles XML, but renders it as CSS, and Mozilla (Netscape) is still experimenting with XML support.

Xmodem
Originally developed in 1977, Xmodem is one of the most popular file-transfer protocols. Although Xmodem is a relatively simple protocol, it is fairly effective at detecting errors. It works by sending block of data together with a checksum and then waiting for acknowledgment of the block's receipt. The waiting slows down the rate of data transmission considerably, but it ensures accurate transmission. Xmodem can be implemented either in software or in hardware. Many modem, and almost all communications software packages, support Xmodem. However, it is useful only at relatively slow data transmission speeds (less than 4,800 bps).
Enhanced versions of Xmodem that work at higher transmission speeds are known as Ymodem and Zmodem.

XPointer
XML Pointer Language.

XSL
Extensible Style Language, a specification for separating style from content when creating HTML or XML pages. The specifications work much like templates, allowing designers to apply single style documents to multiple pages. XSL is the second style specification to be offered by the World Wide Web Consortium (W3C). The first, called CSS, is similar to XSL but does not include two major XSL's innovations -- allowing developers to dictate the way Web pages are printed, and specifications allowing one to transfer XML documents across different applications. W3C released the first draft of XSL in August 1998, and promotes the specifications as helpful to the Web's speed, accessibility, and maintenance.

XSLT
Extensible Style Language Transformation, the language used in XSL style sheets to transform XML documents into other XML documents. An XSL processor reads the XML document and follows the instructions in the XSL style sheet, then it outputs a new XML document or XML-document fragment. This is extremely useful in e-commerce, where the same data need to be converted into different representations of XML. Not all companies use the exact same programs, applications and computer systems.

Yettie
Young Entrepreneurial Technically-orientated Twenty-something.

Ymodem
An asynchronous communications protocol that extends Xmodem by increasing the transfer block size and by supporting batch file transfers. This enables you to specify a list of files and send them all at one time.

Z-Buffering
An algorithm used in 3-D graphics to determine which objects, or parts of objects, are visible and which are hidden behind other objects. With Z-buffering, the graphics processor stores the Z-axis value of each pixel in a special area of memory called the Z-buffer . Different objects can have the same x- and y-coordinate values, but with different z-coordinate values. The object with the lowest z-coordinate value is in front of the other objects, and therefore that's the one that's displayed.
An alternate algorithm for hiding objects behind other objects is called Z-sorting. The Z-sorting algorithm simply displays all objects serially, starting with those objects furthest back (with the largest Z-axis values). The Z-sorting algorithm does not require a Z-buffer, but it is slow and does not render intersecting objects correctly.

ZIP
Zone Information Protocol. A session-layer protocol used by AppleTalk to map network numbers to zone names.

Zmodem
A file transfer protocol for modems that send data from an Internet host to a PC.

Zombie
(1) A computer that has been implanted with a daemon that puts it under the control of a malicious hacker without the knowledge of the computer owner. Zombies are used by malicious hackers to launch DoS attacks.
Zombies are also referred to as zombie ants.

(2) In UNIX operating systems, a zombie is a "child" program that was started by a "parent" program but then abandoned by the parent.

Zone
A logical grouping of network devices in AppleTalk.

ZV Port
Zoomed Video PORT, a port that enables data to be transferred directly from a PC Card to a VGA controller. The port is actually a connection to a zoomed video bus.

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