Every animated object in Unity uses an Animator component and an Animator Controller asset. The component is responsible for playing animations in runtime. It has a number of parameters that we have to set or we can use to tweak the component's functionality:

• Controller: This is the field we have to attach the Animator Controller asset to. It determines which animation graph the Animator component will use.

• Avatar: In Unity, Avatars are rig definitions. For instance, if we have multiple files containing animations with the same Generic rig, we should use the same Avatar for all of them. You can find more information about it in the Using animations from multiple assets recipe.
• Apply Root Motion: With this checkbox, we can turn the root motion on and off. It can be useful when we have animations with root motion but don't want to use the root motion definition for a given character.
• Update Mode: This parameter tells Unity in which update the animations should be evaluated. The Normal option makes the animations synchronized with the normal Update() call, the Animate Physics option synchronizes animations with the physics FixedUpdate() call, and the Unscaled Time option synchronizes the animation with the normal Update() call, but disables animation time scaling (the animation is played with 100 percent speed regardless of the Time.timeScale variable value).
• Culling Mode: This parameter tells Unity when to turn off the animation playback on a given Animator. The Always Animate option makes the Animator always play animations (event when off-screen), the Cull Update Transforms option culls Retarget and IK Transforms when the Animator is not visible on screen, and the Cull Completely option disables the animation completely when the Animator is not visible on screen.

The Animator Controller asset stores a graph of animations (animation states) and defines the rules of switching between them, blending them, and so on. The controller (asset) is attached to the component's Controller field (the component is attached to a character prefab or a character placed in the scene). Many objects or characters can share the same Animator Controller if they use the same animations (have the same rigs or are humanoid characters).