Elastic deformation is a reversible change in the size and shape of an object due to an applied force, where the object returns to its original form once the force is removed. There are two types of deformation - elastic deformation, which is reversible, and plastic deformation, which is irreversible but involves initial elastic deformation allowing partial recovery of shape. An experiment can study elastic deformation using a spring, masses, and measuring equipment to draw extension-load graphs.