vaporware Refers to either hardware or software that exist only in the minds of the marketing department and never was offered for sale.

variable-Q equalizer See: proportional-Q equalizer

VCR (Video cassette Recorder)  A device that can record and playback video to and from video cassette tapes.

vector Mathematics. A quantity, such as velocity, completely specified by a magnitude and a direction.

VESA ( Video Electronics Standards Association)  A trade organization formed mainly to propose and maintain standards for the electronics industry.  Widely known for the long list of graphic display modes for video display devices.

VGA ( Video Graphics Adaptor )  Term for video cards used in personal computers and there outputs.  Includes standards for display mode of a computer display, in particular the maximum number of colors and the maximum image resolution (in pixels horizontally by pixels vertically

Videoconferencing Communication with remote users that includes two way video and audio.

virus A self-replicating program released into a computer system for mischievous reasons. Once triggered by some preprogrammed event (often time or date related), the results vary from humorous or annoying messages, to the destruction of data or whole operating systems.

VLSI (very-large-scale integration) Refers to the number of logic gates in an integrated circuit. By today's standards, a VLSI device could contain up to one million gates.

Voice Tracking  Electrical circuits that track the movements of a speaker by measuring the sound arriving at the camera from spoken voice.

volatile Refers to a memory device which loses any data it contains when power is removed from the device. Examples would include static and dynamic RAMs.

volt Abbr. E, also V. The International System unit of electric potential and electromotive force, equal to the difference of electric potential between two points on a conducting wire carrying a constant current of one ampere when the power dissipated between the points is one watt. [After Count Alessandro Volta.]

Volta, Count Alessandro (1745-1827) Italian physicist who invented the battery (1800). The volt is named in his honor.

VOX ( Voice Activated Switch ) An electrical circuit that controls one or more functions of the system based on the presence of a voice at a particular microphone.

VRML (virtual reality modeling language) A developing standard for describing interactive 3D scenes delivered across the internet. In short, VRML adds 3D data to the Web.

VU meter (volume units) The term volume units was adopted to refer to a special meter whose response closely related to the perceived loudness of the audio signal. It is a voltmeter with standardized dB calibration for measuring audio signal levels, and with attack and overshoot (needle ballistics) optimized for broadcast and sound recording. Jointly developed by Bell Labs, CBS and NBC, and put into use in May, 1939, VU meter characteristics are defined by ANSI specification "Volume Measurements of Electrical Speech aned Program waves, " C16.5-1942 (original issue date; use latest). 0 VU is defined to be a level of +4 dBu for an applied sine wave. The VU meter has relatively slow response. It is driven from a full-wave averaging circuit defined to reach 99% full-scale deflection in 300 ms and overshoot not less than 1% and not more than 1.5%. Since a VU meter is optimized for perceived loudness it is not a good indicator of peak performance. Contrast with PPM.