Key frame
In animation, a key frame is a frame in an animated sequence of frames that was drawn or otherwise constructed directly by the user rather than generated automatically, e.g. by tweening.
In video compression, a key frame or I frame is a frame encoded without reference to any images in another frame.
In non-linear digital video editing, a key frame is a frame used to indicate the beginning or end of a change made to the signal. For instance, a key frame could be set to indicate the point at which audio will have faded up or down to a certain level.
