1. In animation, the basic unit of time measurement. The duration of an animation is changed by increasing or decreasing its frame range. Typically, 30 frames of animation correspond to one second on NTSC video tape (25 frames for PAL video tape, and 24 frames for film). 2. In film and video post-production, a standard unit of film or video information consisting of a single complete image. 3. The act of composing an image or scene by specifying the outer border. 4. In MEL animation expressions, an internal variable that returns the current frame position along the timeline. This variable can be used in the Attribute Editor to go to the current frame.