While recording animations as Timeline tracks is very convenient, it does have its limitations. These animations "live" in Timeline. But sometimes, you want to treat animations as assets in their own right. For example, you would use Animation Clips if you want an animation to loop repeatedly or transition between movements, blend their actions, and then apply the same set of animation curves to many different objects.
Animators were the standard way of managing Animation Clips in Unity before Timeline. It uses an Animator Component, an Animator Controller, and an Animation Clip. Fortunately, if you create a new Animation Clip on an object, Unity creates each of these items for you. But it's important to understand how they fit together.
Briefly, from the Unity Manual (https://docs.unity3d.com/Manual/animeditor-CreatingANewAnimationClip.html):
