Call manager
The component that implements the media-specific signaling protocol for virtual circuit (connection) management on connection-oriented networks.

CardBus
A 32-bit PC Card.

CD-ROM
Compact disc read-only memory. A laser-encoded optical memory storage medium.

CDFS
CD-ROM file system, which controls access to the contents of CD-ROM drives.

Channel
A push technology that allows users to subscribe to a Web site to browse offline, automatically display updated pages on their screen savers, and download or receive notifications when pages in the Web site are modified.

Channel bar
An area on the user's Active Desktop that displays all the subscribed channels.

Channel Definition Format (CDF) file
A file that specifies the content of an Active Channel and when and how that content should be delivered to the user.

CHAP
Challenge Handshake Authentication Protocol.

Checksum
A calculated value used to test data for the presence of errors that can occur when data is transmitted or when it is written to disk.

Chip set
A collection of integrated circuits designed to be used together for a specific purpose.

Clean boot
Booting or starting a computer using the minimum system files in the operating system.

Clean installation
Installation of an operating system on a new computer or a computer with a reformatted hard disk.

Client
A process that requests a service provided by another program (called a server). See server.

Client for Microsoft Networks
A 32-bit, protected-mode file system driver to support all Microsoft networking products that use the SMB file-sharing protocol.

Cluster
A specified number of sectors grouped together by the FORMAT command. The number is determined by the size of the logical drive. A cluster is the smallest storage unit for storing files.

Code page
An internal table that the operating system uses to relate the keys on the keyboard to the characters displayed on the screen.

Codec
Compression/decompression technology for digital video and stereo audio.

Cold docking
Insertion or removal of a device in the system before which the device must be powered off or restarted.

Compatibility mode
A mode protocol defined in IEEE P1284 that provides a byte-wide channel from a computer to a peripheral.

Component Object Model (COM)
The object-oriented programming model that defines how objects interact within a single application or between applications. In COM, client software accesses an object through a pointer to an interface—a related set of functions called methods—on the object.

Compressed volume file (CVF)
A file with read-only, hidden, and system attributes, and that contains a compressed drive.

Container applications
Applications that maintain compound documents.

Cookies
A means by which, under the HTTP protocol, a server or a script can maintain state or status information on the client workstation. In other words, a cookie is bits of information about a person's visit to a Web page. A cookie can include such information as the way a Web page was customized or how a visitor shopped on a Web site, or it can be used to track repeat visits.