Synonyms: Spam, Junk e-mail
Spam is the name commonly given to unsolicited e-mail. It is effectively unwanted advertising, the e-mail equivalent of physical junk mail delivered through the post or from unsolicited telemarketing calls.
Unicode, used in Microsoft® Windows® NT, Windows 2000 and Windows XP, succeeded ASCII as a means of using binary codes to represent text characters used in the world’s principal languages.
The Unix operating system originated at AT&T’s Bell Labs in 1969. Unix is an open source operating system. Since it is not owned by a single vendor, many different Unix versions have been developed since its creation (including Unix-derivative operating systems like Linux). The Open Group holds the ‘Single UNIX Specification’ and the UNIX® trademark and certifies different Unix implementations.
The URL specifies the address of a piece of content on the World Wide Web. The request is made by typing the URL into the web browser, or by clicking on a hyperlink (or link for short): this link may be specified on a web page or in a piece of text in a document, spreadsheet, etc.
UDP is a protocol used to transfer data (in the form of ‘datagrams’) across the Internet. Unlike TCP/IP, UDP doesn’t split up messages and re-assemble them at the other end. It is useful for sending small amounts of data, since it saves processing time that would be used to re-assemble packets.
USB provides a ‘plug-and-play’ standard for connecting many peripheral devices to a computer simultaneously, without the need for a specific device adapter card for each device. USB allows up to 127 devices to connect to a single computer and allows for rapid transfer of data.
USB 1.1 (the original USB specification, developed by Compaq, IBM, DEC, Intel, Microsoft and Northern Telecom) supports data speeds of up to 12Mbps. USB 2.0 (developed by Compaq, Hewlett Packard, Intel, Lucent, NEC and Philips) supports data transfer speeds of up to 480Mbps.
Where a file is transferred from one computer to another, the sender is said to upload the file. For example, anti-virus updates are uploaded by an anti-virus vendor to their server, to make them available for users of their software.