Animation Clips:官方解释为:contain information about how certain objects should change their position, rotation, or other properties over time. Each clip can be thought of as a single linear recording. 自己理解为:某个特定物体的一个动画片段,表现为(Component的)属性在时间轴上的关键帧动画(骨骼动画可能不同),是状态机中的一个State。