Final Cut Pro X: keyframe
A control that denotes the value of a video or audio effect parameter at a particular point in the project. When two keyframes with different values are set in Final Cut Pro, a transition from one value to another is calculated, resulting in a dynamic change to that parameter.
The word keyframe comes from the traditional workflow in the animation industry, where only important (key) frames of an animated sequence were drawn to sketch a character’s motion over time. After the keyframes were determined, an in-between artist drew all the frames between the keyframes.