Animation Clips are one of the core elements to Unity’s animation system. Unity supports importing animation from external sources, and offers the ability to create animation clips from scratch within the editor using the Animation window.
Animation from External Sources
Animation clips imported from external sources could include:
Humanoid animations captured at a motion capture studio
Animations created from scratch by an artist in an external 3D application (such as 3DS Max or Maya)
Animation sets from 3rd-party libraries (eg, from Unity’s asset store)
Multiple clips cut and sliced from a single imported timeline.
Animation Created and Edited Within Unity
Unity’s Animation Window also allows you to create and edit animation clips. These clips can animate:
The position, rotation and scale of GameObjects
Component properties such as material colour, the intensity of a light, the volume of a sound
Properties within your own scripts including float, int, Vector and boolean variables
The timing of calling functions within your own scripts
Animation System Overview
Animation from external sources
Is something described here not working as you expect it to? It might be a Known Issue. Please check with the Issue Tracker at issuetracker.unity3d.com.