The U on iTunes - Terms
Codec
Codec is a device or program
capable of performing encoding and decoding on a digital data
stream or signal.
Codecs (in the modern, software sense) encode a stream or signal
for transmission, storage or encryption and decode it for viewing
or editing. Codecs are often used in videoconferencing and streaming
media applications. A video camera's ADC converts its analog signals
into digital signals, which are then passed through a video compressor
for digital transmission or storage. A receiving device then runs the
signal through a video decompressor, then a DAC for analog display.
A "codec" is a generic name for a video conferencing unit.
Users of iTunes U will use codec to encrypt their information
so people can download it and decode it to watch or listen to
their information.