U

U for URL

abbreviation / acronyms	term	definition
U2F	Undetectable and Untraceable Fraud	A major issue for information technology is fraud made possible by technology and electronic transactions, especially crimes that leave no trace and no audit trail.
UA	Upgrade Advantage	A Microsoft software license program.
UAC	User Account Control	A security technology in Windows Vista that reduces exposure to attacks by running in nonadministrative mode, even when logged on with an administrative account, unless and until administrative privileges are required to perform a task.
UART	universal asynchronous receiver-transmitter	A module composed of a single integrated circuit, which contains both the receiving and transmitting circuits required for asynchronous serial communication.
UAT	User Acceptance Test	Normally a suite of documented tests, derived from a requirements or functional specification and agreed with a client, that when successfully completed indicate that a produced product is acceptable
uauth	user authentication	user authentication
UBE	unsolicited bulk email	a formal term for spam. The most common type of UBE is UCE: bulk email that is trying to get the recipient to buy some product or service.
µBGA / uBGA	Micro Ball Grid Array	Next to bare die, uBGA is the smallest of the chip-scale packaging options.
UBR	Undefined Bit Rate	An economical class of QoS on a moment-to-moment basis, without guaranteeing service levels.
UC	Unified communications	UC is a direct result of the convergence of communications and applications. Differing forms of communications historically have been developed, marketed and sold as individual applications. In some cases, they even had separate networks and devices.
UC2	Unified Communications and Collaboration	IBM portfolio based on Lotus Notes messaging, Sametime collaboration products and the Eclipse client framework
UC&C (or UCC)	Unified Communications & Collaboration	Mashups, consoles, APIs and packaged clients will enable other collaboration services to be blended into a mix that includes e-mail, RSS feeds, calendars, blogs, tasks, wikis, personal pages and discussion threads.
UCB	unit control block	A control block in common storage that describes the characteristics of a particular I/O device on the operating system
UCC	Uniform Code Council	Data Model standard
UCCW	Ultimate custom widget	versatile Android widgets
UCD	Unicode Character Database Uplink Channel Descriptor User-centered design	Consists of a number of data files listing character properties and related data along with a documentation file that explains the organization of the database and the format and meaning of the data in the files. See also http://www.unicode.org a concept in the IEEE 802.16 (WiMAX) network, which describes the uplink burst profile a design philosophy where the end-user’s needs, wants and limitations are a focus at all stages within the design process and development lifecycle.
UCE	Unsolicited Commercial Email	Electronic junk mail advertising a product, service, or web site, where the recipient did not request to receive the message.
UCM	Unified Change Management Unified Computing System Universal Content Management Universal Customer Master Use Case Maps	A Change Management (CM) concept implemented by Rational Software Corporation (acquired by IBM) Cisco next-generation data center platform accelerates the delivery of new services simply, reliably, and securely through end-to-end provisioning and migration support. Oracle's unified platform for WCM, document anagement, digital asset management and retention management Siebel MDM product, acquired by Oracle a visual representation of the requirements of a system, using a precisely defined set of symbols for responsibilities, system components, and sequences. www.usecasemaps.org
UCP	Ubuntu Certified Professional	first introduced in May 2006 is a computer based examination about the Ubuntu operating system. It is administered by the LPI foundation.
UCS	Universal Character Set	A character set using 16-bit character codes, also called ISO 10646. UCS is a standard defined by the ISO and IEC. A printer feature that permits the use of a variety of character arrays.
uDAPL	User Direct Access Programming Library	a specification and a library that defines a single set of user APIs for all RDMA-capable transports.
UDDI	Universal Description, Discovery and Integration	A method for finding new Web Services by referring to a central directory. The specification for an index of all available Web services which is comparable to a global Yellow-Pages directory. UDDI helps businesses to produce descriptions of the services they offer, pass on details to the registry and thus appear to be a services provider. www.uddi.org
UDF	Universal Disk Format	The volume format of DVD disks.
UDLP	UniDirectional Link Protocol	This protocol is used by inexpensive, receive only antennas to receive data via satellite.
UDMA	Ultra DMA (Ultra Direct Memory Access)	A protocol developed by Quantum Corporation and Intel for disk drives that enables the computer to take advantage of the fast Ultra ATA disk drives.
UDO	Ultra Density Optical	Optical storage technology that increases capacities by using an extremely focused blue laser to write and read data. HP, Sony, and Plasmon collaborated on the UDO standard
UDP	User Datagram Protocol	It is part of the TCP/IP suite of protocols used for data transferring. UDP is a known as a "stateless" protocol, meaning it doesn't acknowledge that the packets being sent have been received. For this reason, the UDP protocol is typically used for streaming media. While you might see skips in video or hear some fuzz in audio clips, UDP transmission prevents the playback from stopping completely.
UDRP	Uniform Dispute Resolution policy	defines how disputes over domain name registrations are resolved in the global top-level domains (.biz, .com, .info, .name, .net, and .org as well as .aero, .coop, and .museum).
UFS	Unix File System	The default disk-based file system under the Unix operating system
UGC	User generated content	UGC covers a range of media content available in a range of modern communications technologies.
UGS	Unsolicited Grant Service	one of the five QoS service types defined in the IEEE 802.16 WiMAX. The 802.16 protocol supports five types of QoS.
UHF	Ultra High Frequency	Electromagnetic frequencies in the range of 300 to 3000 megaherz. Used for some television and radio transmission.
UHV	Ultra High Voltage	a term meaning any amount of voltage in excess of 800,000 volts.
UI	user interface	The connection between the user and a computer's hardware or software that permits the user to work productively with a system or a program. User interface design requires significant skill and attention and has become a recognized specialty.
UIA	Unified Information Access	Information Access provides total insight based on aggregating all types of data and content in one universal index
UL	Underwriters Laboratories Inc.	a world leader in product safety testing and certification, is working with HP on a two-year project to standardize processes and technologies.
ULH	ultra-long-haul	100Gbps optical system
ULV	Ultra Low Voltage	A class of processors that are deliberately under clocked to use less power at the expense of performance.
UM	Unified messaging	UM is an extension of voice mail that enables subscribers to access and manage messages, such as voice mail, fax mail and e-mail, from a single-user interface. Typical e-mail clients include Microsoft Outlook, Lotus Notes and Novell GroupWise. The telephone is another user interface alternative for unified messaging.
UMA	Unified-Memory Architecture Unlicensed Mobile Access Upper Memory Area User Mode Audio	Allows the CPU and video controller to share the same main memory and 64 bit data path. One or two MB of main memory is allocated to video via a Win 95 utility or in the PCs setup. provides access to GSM and GPRS mobile services over unlicensed spectrum technologies, including Bluetooth and 802.11, typically using a broadband connection to "backhaul" traffic to the service provider. In a PC, the memory area between 640K and 1024K. Under DOS, this memory area is ordinarily designated for use by the ROM BIOS and display, and is unavailable for use by other programs. Together with PUMA, is an engine in the Windows Vista Protected Environment that provides a safer environment for audio playback, as well as checking that the enabled outputs are consistent with what the content allows
UMB	Ultra Mobile Broadband upper memory block	the brand name for the project to improve the CDMA2000 mobile phone standard for next generation applications and requirements. An upper memory block is a contiguous block of memory starting at an address above 640 KB. MS-DOS distinguishes between conventional memory (addresses between 0 and 640 KB) and upper memory (addresses above 640 KB).
UMC	ultra modular computing	The radical adoption of modular principles based on using commodity components in a standardized architecture in order to simplify the environment for creating, delivering, and operating applications within an enterprise.
UMID	Unique Material IDentifier	A methodology for materials suppliers to code a material that only THEY supply. While used in the computer and chip making industries, it is also used in other industries such as medical, food processing and weapons, to name a few.
UML	Unified Modeling Language	A standardized visual notation for communication about system specifications and design details. Initially created at Rational Software (now part of IBM).
UMS	Unfied Messaging Systems	a technology that should allow users to access messages sent in different formats through one single interface.
UMTS	Universal Mobile Telecommunication System	UMTS is envisioned as the successor to Global System for Mobile Communications (GSM). UMTS signals the move into the third generation (3G) of mobile networks.
UNC	Uniform / Universal Naming Convention	this is a syntax for a network resource, file or printer, in the standard format: \\SERVER\QUEUE or \\SERVER\VOLUME\DIRECTORY
UNI	User-to-Network Interface	ATM User Network Interface is an ATM Forum specification of the interface between an ATM user device and the ATM network.
Unicode	UNIversal CODE	A 16-bit character set defined by ISO 10646.
UNR	Ubuntu Netbook Remix	Canonical-sponsored netbook-optimized Linux distribution that is based on Ubuntu. It has been available since Ubuntu 8.04 "Hardy Heron". UNR is an optional preinstalled Linux on some netbooks such as Dell Inspiron Mini 10v and the Toshiba NB100.
UOL	Universo Online	UOL is a Brazilian online service provider and ISP.
UOW	unit of work	In advanced program-to-program communications, the amount of processing that is started directly or indirectly by a program on the source system. A recoverable sequence of operations performed by an application between two points of consistency. A recoverable sequence of operations within an application process.
UPA	user printable area	The area within the valid printable area (VPA) where user-generated data can print without causing an exception condition.
UPC	Universal Product Code	The bar code printed on retail merchandise, it contains the vendor's identification number and the product number.
UPnP	Universal Plug and Play	Plug and Play describes devices that work with a computer system as soon as they are connected. UPnP is an extension of this idea that expands the range of Plug and Play devices to networking equipment. Universal Plug and Play uses network protocols to allow a wide range of devices to be interconnected and work seamlessly with each other. www.upnp.org
UPS	Uninterruptible Power Supply	In the technology world, UPS is more than just a brown shipping company. It is also a type of power supply that uses battery backup to maintain power during unexpected power outages.
UPT	Universal Personal Telecommunications	a set of standards developed by the CCITT for wireline personal communications.
URC	Utility Ready Computing	HP's integrated IT compute capacity acquisition program that includes a portfolio of deployment, support, availability, and management services.
URI	Uniform Resource Identifier	An address for s resource available on the Internet. The first part of a URI is called the "scheme". the most well known scheme is http, but there are many others. Each URI scheme has its own format for how a URI should appear. A compact string of characters for identifying an abstract or physical resource.
URL	Uniform Resource Locator	The standard way to give address of any resource on the Internet that is part of the WWW.The most common way to use a URL is to enter into a WWW browser program, such at Netscape, or Lynx.
URN	Uniform Resource Name	A URI that is supposed to be available for along time. For an address to be a URN some institution is supposed to make a commitment to keep the resource available at that address.
uRPF	Unicast Reverse Path Forwarding	limit the malicious traffic on an enterprise network
URT	universal receiver transmitter User Registration Tool	A circuit which is used for synchronous, asynchronous, or combined synchronous/asynchronous communications, and which contains a serial-to-parallel converter for data transmitted out of the computer and a parallel-to-serial converter for data coming in. Dynamic authorization and policy control framework that manages access to the LAN by partitioning user traffic through VLANs
USB	Universal Serial Bus Upper Side Band	an external bus standard that supports data transfer rates of 12 Mbps. Upper Side Band in HAM and commercial radio
USENET	USEr's NETwork	A world-wide system of discussion groups, with comments passed among hundreds of thousands of machines. Not all USENET machines are on the Internet. USENET is completely decentralized, with over 10,000 discussion areas, called newsgroups.
USF	Universal Service Fund	Financial mechanism that helps compensate phone companies for providing access to telecom service at reasonable and affordable rates across the country.
USG	UNIX Systems Group	The division of Novell concerned with UNIX and UNIX products.
USHER	United States Higher Education Root Certificate Authority	USHER is a public key infrastructure.
USL	UNIX System Laboratories	The division of AT&T which was responsible for UNIX from 1990 until it was acquired by Novell in 1993.
USM	Unifed Service Model Unsharp masking	CA extensible schema that models both entities and rela- tionships as well as policies and rules that govern how the Catalyst Services federate, correlate and reconcile data and capabilities A process used to sharpen images.
USMT	User State Migration Tool	Tool to migrate user files and settings during large deployments of Microsoft Windows XP and Microsoft Windows Vista® operating systems
USO	universal service obligation	The obligation under the Telecommunications Act 1997 to ensure that standard telephone services, payphones and prescribed carriage services are reasonably accessible to all Australians on an equitable basis, wherever they reside or carry on business.
USP	Universal Storage Platform usage sensitive pricing	Hitachi VM that delivers controller-based virtualization, logical partitioning and universal replication for open systems and mainframe environments in a rack mounted storage services platform. Charge for service based on the amount of use.
usr	Unix System Resources	In any unix (and variants like linux) system the /usr directory
USRT	Universal Synchronous Receiver Transmitter	A circuit which is used for synchronous data communications via the serial port on a computer. It converts data into serial form for transmission.
USS	unformatted system service	A communications function that translates a character-coded command, such as a LOGON or LOGOFF command, into a field-formatted command for processing by formatted system services.
UT	Upper Tester	Representation in ISO/IEC 9646 of means of providing, during test execution, control and observation of upper service boundary of IUT, as defined by chosen Abstract Test Method.
UTF-8	Unicode Transformation Format 8	a method for converting 16-bit Unicode characters to 8-bit characters. This format supports all of the world's languages, including those that use non-Latin 1 characters.
UTM	Unified Threat Management Universal Transverse Mercator	a comprehensive security product that includes protection against multiple threats. A UTM product typically includes a firewall, antivirus software, content filtering and a spam filter in a single integrated package. one of many different mathematical projection models upon which satellite-derived positions can be translated into a coordinate system that orresponds to positions derived through standard maps.
UTP	unshielded twisted pair	a type of cable used in most telephone networks and some computer networks. Pairs of unshielded wires are twisted to protect against electromagnetic interference, rather than relying on a metal sheath around each pair of wires to protect against interference.
UTSL	Use The Source Luke	meaning read the source code
UUCP	Unix to Unix Copy	A file exchange protocol between two host computers. Used as part of many firewall mechanisms.
UUEE	Unix-to-Unix Encode	A tool for transferring files through e-mail.
UUENCODE	Unix to Unix Encoding	A method for converting files from Binary format to ASCII text so that they can be sent across the Internet via email.
UUG	Unix User Group	There are UUGs worldwide
UUID	Universally Unique Identifier	The 128-bit numerical identifier that is used to ensure that two components do not have the same identifier.
UUNET	UNIX to UNIX Network	The first Internet access provider, founded in 1987 in Fairfax, Virginia
UUT	Unit Under Test	refers to some type of electrical apparatus connected to test instrumentation. The apparatus can range from a simple circuit to a complex subsystem such as a mobile phone, base station or MSC.
UV	UltraViolet light	UV is used in the electronics world to erase EPROMs and similar devices. An invisible band of radiation at the high-frequency end of the light spectrum.
UWB	Ultra-Wide-Band	also called digital pulse, is a wireless technology defined in IEEE 802.15.3 for transmitting digital data over a wide swath of the radio frequency spectrum with very low power.
UWIN	Unix for WINdows	Software that enables Unix software to be executed on a Windows platform
UXP	user experience	user experience
	U	U is the standard unit of measurement for rack-mounted equipment. Racks can be used to house servers, hard drives, switches, routers, and other computer hardware. They are also used for mounting audio and video equipment. 1U is equal to 1.75 inches.
	undead	An undead object is an object that cannot be proven to be dead by the garbage collector, but whose liveness is dubious.
	Unix	A computer operating system (the basic software running on a computer, underneath things like word processors and spreadsheets). Unix is designed to be used by many people at the same time (it is multi-user) and has TCP/IP built-in.
	up-link / uplink	A term used in satellite communications to describe the earth station and the transmit ted signal to a communications satellite .
	USBlyzer	A software USB Protocol Analyzer for Windows that displays USB Descriptors and captures and analyzes the activity of USB devices in real time.