a) An independent signal path. Stereo recorders have two such channels. Quadraphonic ones have four.

b) A digital medium that stores or transports a digital television stream.

c) A term mainly used to describe the configuration of audio tracks. For Dolby Digital there are six channels (left, center, right, left rear, right rear and low frequency effects). For linear PCM and MPEG audio, there are eight channels. All DVD players are required to have a two-channel downmix output, which is a stereo version produced from the intrinsic channels on the disc if there are more than two channels on the disc.