UART (Universal Asynchronous Receiver Transmitter)
The UART manages serial communications. Serial ports are managed by a UART. A modem also has a UART to handle its transmissions.
UNIX (UNiplexed Information and Computing Service)
Originally called UNICS, UNIX is a smaller multitasking operating system with excellent networking capabilities that can be installed on almost any computer.
UPS (Uninterruptable Power Supply)
A UPS prevents a computer from shutting off in the event of a power outage. The computer and other components are plugged into the UPS, which has a battery capable of providing power for several minutes. This gives the user time to shut the computer down properly and not loose any of his or her current work. Most UPS units come with software that will close programs and shut the computer down automatically.
URL (Uniform Resource Locator)
The address of documents and resources on the Internet. Every item on the Internet has an address. A Web browser uses the URL to retrieve its intended target.
USB (Universal Serial Bus)
USB is a 4 pin interface capable of connecting up to 127 devices that operate at transfer speeds up to 12Mbits per second. USB technology is significantly faster than a regular serial port. Devices can be plugged in and installed without shutting the computer down. USB is plug and play compliant. It is also one of the easiest ports for adding expansion devices.