The term codec is also an acronym that stands for
"compression/decompression." A codec is an algorithm, or
specialized computer program, that reduces the number of bytes
consumed by large files and programs.
In order to minimize the amount of storage space required for a
complicated file, such as a video, compression is used. Compression
works by eliminating redundancies in data. Compression can be done
for any kind of file, including text, programs, images, audio,
video, and virtual reality (VR). Compression can reduce the size of
a file by a factor of 100 or more in some cases. For example, a
15-megabyte video might be reduced to 150 kilobytes. The
uncompressed file would be far too large to download from the Web
in a reasonable length of time, but the compressed file could
usually be downloaded in a few seconds. For viewing, a
decompression algorithm, which "undoes" the compression, would have
to be used.
There are numerous standard codec schemes. Some are used mainly to
minimize file transfer time, and are employed on the Internet.
Others are intended to maximize the data that can be stored in a
given amount of disk space, or on a CD-ROM.
Codecs are used in many popular Internet products, including
QuickTime, Netmeeting, Cu-Seeme, and VDOphone.
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