Unity - Scripting API:

public function Play(stateName: string, layer: int = -1, normalizedTime: float = float.NegativeInfinity): void;

public function Play(stateNameHash: int, layer: int = -1, normalizedTime: float = float.NegativeInfinity): void;

Parameters

stateName	The name of the state the will be played.
layer	The layer where the state is. If no layer is specified or layer is -1, the first state that is found with the given name or hash will be played.
normalizedTime	The normalized time at which the state will play. If no explicit normalizedTime is specified or normalizedTime value is float.NegativeInfinity, the state will either be played from the start if it's not already playing, or will continue playing from its current time.
stateNameHash	The hash of the state. Passing zero will play the current state.

Plays a state.

This could be used to synchronize your animation with audio or synchronize an Animator over the network.