d video at 24 frames per second. video capture board A PC circuit board that can capture the two fields that comprise a single video frame (included in most modern PCs). See also frame grabber. video mail A multimedia version of electronic mail that includes moving or still images that are embedded into the message. Also known as v-mail. video server A specialized file server with enormous hard disc capacities (often measured in terabytes or trillions of Glossary of Terms bytes). A video server stores compressed audio and video images for access. Often called video jukeboxes, these servers provide service to end-users over high- speed networks. video wall Multi-screen video system in which a large number of video monitors or back projection modules together produce one big, bright image. This is achieved by splitting the incoming video signal across many monitors. Video-On-Demand VOD. The ability for subscribers to control when and how they view a movie. VOD delivers features that mimic VCRs (e.g., rewind, pause, fast-forward(. videoconferencing A collection of technologies that integrate video with audio, data, or both and convey the aggregate signal, Real-Time, over distance for the purposes of a meeting between dispersed sites. videophones Telephones with video capability. virtual circuit A seemingly dedicated connection between two points in a packet-switched network. In a virtual circuit, packetized data from multiple devices is placed on the same circuit. virtual private network Virtual private network technology allows an organization to use the Internet as a private network by employing tunneling or data encryption techniques in a firewall. Very Large Scale Integration. voice-activated Microphones that automatically capture and transmit microphones audio at the trigger of a voice. Transmission ceases when the triggering sound stops. Videoconferencing system manufacturers effectively incorporate voice- activated microphones with cameras that capture and transmit images based on who is speaking. voltage Ele