USB Universal Serial Bus
External bus (BUS). The current USB specification, each port (PORT) can simultaneously connect 127 devices and supports Plug and Play (PLUG-AND-PLAY) and you can not turn off the power under conditions of hot-plug (HOT-PLUGGING). USB is a transmission technology specifications, are already 2.0, which supports transfer rate to 480MBPS, is now 480 times as USB 1.1. In addition to faster outside the former, and USB 1.1 compatible, so in the past around the use of USB interface, transmission line, connector specifications are available. And on the current USB transfer size to compete with each other is the IEEE 1394, which we can expect the transfer speed up to 400Mbps, but the two still share a distinction in the use of: USB for PC peripherals such as scanners, storage devices, digital cameras so on, and IEEE 1394 should be placed on the main consumer products such as digital images, audio, multimedia and IA. Related words: IEEE Transmission Specification.

User Interface Computer
User interface, program or system to the user mode of operation of the look and feel and design concepts.

Utility computing
Primarily to promote an ideal business information framework to enable IT services to mimic the way public services, such as water supply, electricity, gas.
In the framework of utility computing, computing services, as readily as electricity and water supply, while according to different industries or different needs of different sectors at any time to provide services on demand (On demand services), including automatic provision of quantifiable, measurable IT resources, including servers, storage, business applications and network resources. Users via an intranet or public internet access computers to obtain computing resources. Billing approach to the use of terms, such as CPU usage in seconds, minutes or hours.
In an ideal situation, the utility computing services provided would allow a gradual reduction of traffic accidents; and through automatic forecast demand, and pre-build server can detect abnormal equipment capacity, followed by early warning, the same can allow enterprises to raise awareness of hardware and software efficiency.
Current information industry, software and hardware vendors scramble to compete for utility computing business opportunities, such as IBM's on-demand computing services to promote (SOD, Services On Demand), Sun Microsystems (Sun) pushing the "NI" framework, and Hewlett-Packard (HP ) newly released live Growth Enterprise (AE, Adaptive Enterprise) strategy, etc., are regarded as the core concept of utility computing to the proposed information architecture. Others, such as VERTIAS, BMC, Computer Associates (CA) and other software vendors have released on demand computing the initial strategy.

UTP Unshield Twisted Pair
Unshielded twisted-pair, local area network (LAN) and telephone wires are frequently used by the two does not increase interference shielding composed of copper winding each other, mutual entanglement can offset a part of the external radio signal interference (INTERFERENCE ). UTP several types of specifications: 1. CATEGORY 1: traditional phone use, does not support data transfer .2. CATEGORY 2: there are four pairs of lines, data transfer rates of up to 4 MBPS.3. CATEGORY 3: there are four pairs of lines, data transmission speeds up to 10 MBPS.4. CATEGORY 4: there are four pairs of lines, data transfer rates of up to 16 MBPS.5. CATEGORY 5: there are four pairs of lines, the same length of wire, CAT 5 winding laps than any other specifications required high and need more specific tools to use, data transfer rate up to 100 MBPS.

UUENCODE Unix-to-Unix Encode
An encoding method, you can use the 8-bit (BIT) format data into a 7-bit ASCII characters in file used in the does not support 8-bit transfer files between systems. UUENCODE is often used as an electronic E-mail (E-MAIL) additional file encoding.