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.

UAT

User Acceptance Testing, also called application testing or end-user testing, is a phase of software development in which the software is tested in the real world by its intended audience. UAT is often the last phase of the software testing process and is performed before the tested software is released to its intended market.

UAV

Unmanned Aerial Vehicle.

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.

UGC

User Generated Content.

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.

unsubscribe rate

An unsubscribe rate indicates the percentage of customers who have unsubscribed or opted out of a mailing list after an email campaign.

Uploading

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

UPS

Uninterruptible Power Supply or Uninterruptible Power Source, is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails.

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.

Utility Computing

A service provisioning model in which a service provider makes computing resources and infrastructure management available to the customer as needed, and charges them for specific usage rather than a flat rate. Similar to On Demand Computing .

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.