Josh References Glossary U

UCE
See Unsolicited Commercial Email (UCE).

UDP
See User Datagram Protocol (UDP).

UFS
See Unix File System (UFS).

UI
See user interface (UI).

UID
See user ID (UID).

UI server
The display manager and command/callback engine.

undo
Back up one step; discard the most recent change.

unicast
When one individual, specific host sends a message to another individual, specific host. See also anycast, broadcast, multicast.

Uniform Resource Locator (URL)
Also called a Universal Resource Locator. The pointer that defines the access method, host, path name, and file name to some reference or resource on an internet, accessible via a WWW browser. Defined in RFC 1738 and RFC 1808.

Universal Coordinated Time (UTC)
The modern (post 1972) global coordinated time system, explained in fuller detail.

Unix File System (UFS)
The generic name for the modern implementations of the Berkeley fast file system (FFS). A hierarchical file system in common use on Unix systems.

Unix to Unix Copy (UUCP)
A file exchange protocol between two host computers. Used as part of many firewall mechanisms. See also firewall.

unshielded twisted pair (UTP)
A cable where the pair of wires that carry the signal are not shielded from external electromagnetic interference.

Unsolicited Commercial Email (UCE)
Electronic junk mail advertising a product, service, or web site, where the recipient did not request to receive the message. See also spam.

URL
See Uniform Resource Locator (URL).

USENET news
A hierarchical organization of news articles and groups containing information. The information ranges from technical (comp.*) to entertainment and social activities (rec.*, soc.*) to debates (talk.*).

user
The ultimate source or destination of a message, or the ultimate cause or effect of an action.

User Datagram Protocol (UDP)
A connectionless and therefore inherently unreliable data protocol (RFC 768) where data is sent but not acknowledged. No guarantee of delivery is defined in the UDP protocol; no attempt to recover from data loss is performed. See also IP family.

user ID (UID)
A numeric value for the user's account identification.

user interface (UI)
The interface between the user and the program. See also command line interface (CLI), graphical user interface (GUI), user.

UTC
See Universal Coordinated Time (UTC).

utility
An application, program, or script used to accomplish a specific task.

UTP
See unshielded twisted pair (UTP).

UUCP
See Unix to Unix Copy (UUCP).