CC-Courtesy Copy
A copy of an E-Mail message, sent to an address specified in the "CC" field of the message header. Thus the primary recipient knows to whom copies have been sent.
(See header, E-Mail, BCC.)

Chameleon
A software package including programs that provide Internet services such as Gopher, E-Mail, FTP, IRC, Web browser, etc.  
(See Gopher, FTP, Usenet, E-Mail, browser)

Channel
When talking in IRC, every topic is called a channel. (See IRC.)

Chat 
See IRC.

Client
When one computer is connected to another computer in order to receive information or utilize computer resources, it is called a client.  

Clipboard
On computers working in a graphic interface environment (PC or Mac), this is the temporary storage location for information taken from a document (by performing "copy" or "cut" operation) prior to its being pasted somewhere else. 

Comprehensive 
This engine conducts searches according to server name. (See search engine.)

Compression
A way of shrinking a file in order to save space on your disk and reduce transmission time. (See data compression.)

Compuserve
One of the oldest and largest online services, Compuserve has about 4,000,000 members around the world.  It's name is sometimes abbreviated as CIS.  

Configuration
Specific parameters that define how a computer or a specific application functions (screen resolutions, number of colors, etc.). (See application).

Country code
The last component in a URL address.  A country code consists of two letters, usually indicating the country where the computer is located.  For example, a URL address ending in UK belongs to a computer located in the United Kingdom. (See URL.)

Cyberspace
All computers that can communicate with each other via the various communication networks.  These networks include Internet, Compuserve, America On Line, Prodigy, and others. (See also network, Compuserve, America On Line).