The Animator Component transforms Animation Clips from your Animator Controller into real changes on your avatar. While you can add it manually, Unity automatically places it on any FBX file with an avatar definition.
To do this automatically:
Create from this Model or Copy From Other Avatar.
The Animator Component as seen in the in the GameObject Inspector

The Animator component can be added to any GameObject via the Add Component button in the Inspector.
The animator component has a few usage quirks:
When animating a GameObject, a property’s target path omits the Root Animator GameObject. For example:
If we want to animate Child relative to the Animator on the Avatar, the Animation Clip’s path will be Parent/Child

If we want to animate Child relative to the Animator on the Parent, the Animation Clip’s path will be Child

Adding properties to the Animation window will add property paths relative to the nearest parent Animator component.
The Animation Window changes depending on the nearest Animator component on itself or any parents.

Preview, Record, and other editing features will be unavailable unless you select a GameObject in your Hierarchy with an Animator somewhere above it.

The Animator component has five fields to interact with: