You can use blend shape deformers in different ways, depending on how your scene is set up. You can create all your target shapes on one base object, or you can use a more traditional method of creating separate target objects to create the target shapes.
As well, you can use blend shapes with skinned characters to fix problems that happen after the skin is deformed during animation, or update the skin's mesh to have those changes available before the skin is deformed by joint animation.
See the topics below for information on each of these methods.
For information on creating poses with interpolation for skinned characters, see Pose space deformations.