Stands for "Digital Video."
DV is an early digital videotape format and is the first digital video format made widely available for amateur use. Unlike analog video tape, which encodes audio and video as an analog waveform, DV stores encoded audio and video signals digitally on magnetic tape in a cassette. DV cassette tapes are available in several sizes — the smallest, MiniDV, was widely used on consumer video cameras until cameras with internal flash storage became available.
DV video is typically standard definition (720x480 pixels), although a high-definition version, HDV, supports 720p and 1080i video. The standard-definition DV codec lightly compresses video using an intra-frame method, processing video one frame at a time to make video editing easier (unlike inter-frame encoding, which compresses video by comparing the differences between consecutive video frames). The DV codec is not limited to recording video to magnetic tape; it can also store video as discrete files on hard drives, memory cards, or a camera's built-in flash storage.
Since DV stores audio and video digitally, camcorders can easily transfer video to a computer for playback and editing. DV camcorders export video from the cassette to a computer using a Firewire (IEEE 1394) cable, which can then be edited directly in video editing software without any additional analog-to-digital conversion.