Nonlinear animation allows you to create and edit an animation sequence by arranging smaller animation sequences (known as clips) on a timeline. A clip is a time-independent sequence of animation that you create from an existing animation (keyframe animation, expressions, constraints, and motion capture data - except motion path animation).
Nonlinear animation tools in Maya® TraxTM give you the ability to experiment with your animation sequences and character animations without having to redo all of your work when you want to modify or construct a different animation.
Nonlinear animation is a non-destructive process. You can modify a particular clip’s attributes without affecting the source animation: the source material remains untouched. This makes nonlinear animation useful when you want to experiment, iterate, or change a particular animation sequence.