Unix

An Operating System used by the majority of Internet servers due to its reliability and security features.

Upload

The term used when transferring files from a local machine, such as a home PC to a server, such as an ISP.

UPS

Uninterruptable Power Supply. Essentially a large battery used so that when there is a power failure there is still time to shut down a PC correctly. More modern models actually communicate with the PC to get them to shut down automatically and safely in the event of a power failure.

URL

Uniform Resource Locator. The way in which an Internet server locates a page based on the address used.

USB

Universal Serial Bus. The latest technology in attaching peripherals to a PC, allowing up to 127 devices to attach through a single socket. Developed by companies such as Intel and Microsoft, USB should in the future make things easier for the consumer by doing away with technicalities like DMA and IRQ settings.

Usenet

A network linking thousands of newsgroups into one 'whole'.