Historically, skeletal animation has been tied to a specific rig.
(BTW, in Blender, rigs are called armatures.) Blender has an automatic rigging feature called Rigify. The act of adding a rig to a 3D model is called rigging. Blend shapes (aka morphing) deforms the mesh.There are two common ways to animate a model: For example, a non-animated rock might only have a mesh.
If the left arm bone moves, the left arm part of the mesh follows it. Very roughly speaking, each bone is tied to part of the mesh. A 3D model consists of two basic parts: the mesh (i.e., the skin) and the rig (i.e., the skeleton).
