M, MII: Professional tape formats from Panasonic. The M format was based on VHS technology, and was introduced at about the same time as Beta (in the mid-1980's). The MII format was introduced a few years later to compete with Beta SP. MII uses a different sized cassette. More info: M, MII
MIDI: Musical Instrument Digital Interface. A standard of communication between musical instruments, controllers and computers.
Mid-Shot: A camera framing term, half-way between a wide-shot and a close-up. A mid-shot of a person will show them from about the waist or chest up. More info: Mid-shot, Camera shots
MiniDV: A consumer-level digital video format. More info: The MiniDV Format
Mix (1): A video transition in which one shot gradually fades into the next. AKA crossfade or dissolve. More info: The mix transition
Mixer: A device which accepts multiple signal inputs (video or audio), processes them, and provides one or more outputs. The outputs are "mixes" of the input sources. More info: Audio mixers, Vision mixers
M-JPEG: See Motion-JPEG
Modulate: To "change". A signal can be transmitted via a carrier wave, by modulating the wave to represent the signal.
Monitor: A device used to view a video, graphic or text source, or to listen to an audio source. Video monitors use CRTs (cathode ray tubes), LCDs (liquid crystal displays), and other technologies. Audio monitors generally use cone drivers and horn divers, mounted in speaker cabinets.
Monocular: Related to having vision in only one eye, as opposed to binocular (stereo vision, with two eyes). More info: Depth Perception
Monopod: Camera stand, like a tripod with one leg. Has the advantage of being light and easily portable. More info: Monopods, tripods
Morph: Computer-assisted process in which an image (or video) is gradually transformed (morphosed) into another.
MPEG: Moving Picture Coding Experts Group. A digital video compression standard. More info: The MPEG Format
WMA: Windows Media Audio file, a file format used for delivering digital audio. More info: WMA files
WMV: Windows Media Video file, a file format used for delivering digital video and audio. More info: WMV files
WMVHD: Windows Media Video file which features high-definition resolution. More info: WMVHD files
MS: See Mid-Shot