Shape authoring provides you with different tools to accomplish your shape deformation tasks.
Blend shape deformers let you change the shape of an object into the shapes of target shapes, such as for creating facial animation on a character. You can also use blend shapes to correct deformations on a skinned character's body, for example. You can use the Shape Editor to create and control all the blend shape deformers for an object, as well as create target shapes, set their weights and key them, create in-between shapes, create combination shapes, and so on.
See Blend shape workflows for information on different ways of working with blend shapes, and Target shapes, base shapes, and blend shapes for basic information that will help you understand working with blend shapes.