Creating animated characters in Unreal Engine 4 involves using several different Animation Tools (or Editors), each of which focus on different aspects of animation.
For instance, the Skeleton Editor is where everything starts as it is used to manage the bone (or joint hierarchy) that drives the Skeletal Mesh and the animation. The Skeletal Mesh Editor is used to modify the Skeletal Mesh that is linked to a Skeleton and is the outward appearance of a character. The Animation Editor allows you to create and modify your animation assets and is where the tuning/tweaking of animation assets are done. The Animation Blueprint Editor can be used to create logic that drives what animations a character uses and when as well as how animations are blended together. Finally, the Physics Asset Editor can be used to create and edit the physics bodies that will be used for your Skeletal Meshes collision.
Please refer to each editor for more information: