Vaporware - Software that is announced long before it is ready for sale, and that sometimes never materializes.

V.90 - An International Telecommunication Union (ITU) standard for 56-Kbps modems.

Virus - A rogue computer software program created to 'infect' other computer softwares with copies of itself. Viruses may clone themselves and multiply constantly seeking new hosts. Some viruses are benign serving more as an annoyance, while others are designed to damage programs and data.

Virus Signature - The binary pattern of a virus, used by the antivirus program to detect and eliminate the virus. These signatures are usually updated by Virus Software so it may stop new viruses with new signatures.

Visit - Synonymous with viewing a World Wide Web site.

VPN (Virtual Private Network) - Usually refers to a network in which some of the parts are connected using the public Internet, but the data sent across the Internet is encrypted, so the entire network is "virtually" private for security purposes.

Virtual Machine - 1.(VM).A computer that does not exist as a physical device, but is simulated by another computer. 2.(VM).An IBM virtual data processing system, in which multiple operating systems and programs can be run by the computer at the same time.Each user appears to have an independent computer with its own input and output devices.

Virtual Memory - A way of using disk storage space to make the computer work as if it had more memory. When a file or program is too big for the computer to work with in its memory, part of the data is stored on disk. This virtual storage is divided into segments called pages; each page is correlated with a location in physical memory, or RAM. When an address is referenced, the page is swapped into memory; it is sent back to disk when other pages must be called.The program runs as if all the data is in memory. Win 9x uses a Swap file and WinNT/2000 uses a paging file(s). Since disks are slower, this is much slower than memory itself.

Virtual Reality (VR) - A computer simulation of reality, using 3D graphics and sound effects, often with user interfaces such as special goggles and gloves, to create a lifelike environment for entertainment, experimentation, and training.

VxD (Virtual Device Driver) - A virtual device driver is the component of a device driver that communicates directly between an application and a hardware device. Virtual device drivers organize the flow of data to allow more than one application to access the same hardware without conflict.In the device file name, V stands for virtual and D stands for device.The "x" can be replaced with other characters; for example, VmD means a mouse driver.