V

value

Data associated with a key. A key may have zero or more values. Each value has three parts: a name, a type, and data. See also key.

VCN

Virtual cluster number. See virtual cluster.

vector device

A device that creates text and graphics output by drawing lines.

viewport

A rectangle in device space that is used to specify a transformation between page and device space. The viewport extents are always measured in pixels for a video display or dots for printers.

viewport extent

The width or height of the viewport.

viewport origin

The corner of the viewport from which the extents are measured. (The viewport-origin coordinates are specified with respect to the device-space origin.)

virtual cluster

One of the clusters of a file for which the clusters are in the order in which they are read sequentially in the file. Virtual clusters are distinguished from logical clusters. See also logical cluster.

virtual-key code

A device-independent value that identifies the purpose of a keystroke as interpreted by the keyboard device driver.

visible region

The part of the client area that is visible to the user.

visible window

A window that has the WS_VISIBLE style. A visible window is displayed on the screen and can receive user input.

volatile key

A key that is valid only until the next time the operating system is started. See also key.

volume

A storage medium, such as a disk or tape, that is formatted to contain files and directories. A volume is accessed through a disk drive. In a path, a volume is referenced by the letter of the disk drive that accesses the volume. For example, a fixed disk may be referred to as C. A single volume may be divided into more than one logical volume, also called a partition. Each partition is referenced by a unique volume identifier.