Short for Visual Basic Extension, a reusable software component designed for use in many different applications. While VBXs can be used in other environments, they were initially created for developing Windows applications with Visual Basic. An application developer can use a number of selected VBXs to quickly develop an application. While similar to objects, VBXs do not have two of the properties (inheritance and polymorphism) required by true object-oriented systems.
Many different companies offer specialized VBXs for tasks such as controlling instruments or image handling. However, VBXs are being superseded by ActiveX controls, which are more flexible.
Short for variable bit rate, or Class B quality of service, an ATM bandwidth-allocation service that allows users to specify a throughput capacity (i.e., a peak rate) and a sustained rate but data is not sent evenly. VBR is often used when transmitting compressed packetized voice and video data, such as videoconferencing. Compare with ABR, […]
Short for vertical blanking interval, the part of a television transmission signal that is blanked, or left clear, of viewable content, to allow time for the television’s electron gun to move from the bottom to the top of the screen as it scans images. This blank area is now being used to broadcast closed caption […]
Short for Virtual Address eXtension, Digital Equipment Corporation’s successor to its PDP-11 line of minicomputers. As its name implies, VAX systems feature an operating system — VMS — that supports virtual memory. The VAX was introduced in 1977 and reached its pinnacle of success in the mid-1980s. It has been eclipsed by RISC -based workstations, […]
Virus Application Programming Interface, or Virus API (VAPI) is also referred to as Antivirus API (AVAPI), or Virus Scanning API (VSAPI). Virus Scanning API 1.0 was introduced in Microsoft Exchange Server 5.5 Service Pack 3 (SP3) and was standard until the release of Exchange 2000. Many improvements have been made to Virus Scanning API 1.0 […]