Animation
Animation assets are used to play a single animation on a 3D model. Animations are imported by uploading a 3D scene (such as an FBX file) that contains animation data. The animation data is extracted from the uploaded file by the asset pipeline and a Target asset is created for use in the game.
Animation Preview
The Inspector has a viewer that allows you to preview animations alongside template or model assets. This is useful when you have a single animation that can be applied to different character rigs.

There is also a viewer in the Animation State Graph Editor when selecting states in the graph. When selected, all entities in the scene that use the graph are listed and can be selected for preview.
