When a force acts on an object, the object may change shape by bending, stretching or compressing - or a combination of all three shape changes. However, to change the shape of a stationary object there must be more than one force acting to do the following:
Bend an object's ends past each other, eg when an Olympic diver stands on the end of a diving board.
Pull an object's ends apart, eg when a rubber band is stretched.
Push an object's ends together, eg when an empty drinks can is squashed.
A change in shape is called deformation:
A rubber band undergoes elastic deformation when it is stretched when a force is applied, and when it returns to its original shape when the force is removed. A metal drinks can undergoes inelastic deformation when it is squashed.