UDMA: Ultra Direct Memory Access - UDMA defines a new protocol for the interface between the hard drive and the computer. It improves upon the ATAPI/EIDE standard by doubling data transfer rates to 33MB/sec, which translates into faster disk reads and writes. For users to take advantage of UDMA, both their system and hard drive must support the protocol. UDMA retains backwards compatibility for previously existing hardware.
Unix: Described by one of its developers as "a weak pun on Multics" (which was an experimental, time-sharing operating system at Bell Labs in the 1960s), Unix took off in the early 1970s as a general-purpose operating system. Since much of the Internet is hosted on Unix machines, the OS took on a new surge of popularity in the early 1990s. Unix comes in many flavors and runs on a variety of platforms, which makes its development a subject of widespread discussion.
Unzip: To decompress a file that has been compressed using the zip format. Tools like WinZip or WinRar can extract these.
Uplink Port: Special port on a hub or switch that connects to another hub or switch to expand port density.
Upload: Uploading, can refer to the sending of data from a local system to a remote system such as a server or another client with the intent that the remote system should store a copy of the data being transferred, or the initiation of such a process. See Download
USB: Universal Serial Bus - High speed plug and play standard that supports data transfer rates of 12 Mbps. 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.
Usenet: Usenet is a worldwide network of thousands of Unix systems with a decentralized administration. The Usenet systems exist to transmit postings to special-interest newsgroups covering just about any topic you can imagine (and many you wouldn't even want to imagine).