Does a stretched band have energy stored in the form of potential energy or kinetic energy?

A stretched band can return to its normal state if it is
allowed to do so. The energy stored in a stretched band is in the form of potential
energy which arises due to the position of the particles that make up the band. This
gets converted to kinetic energy when the band is no longer being
stretched.

Kinetic energy is energy in a moving particle
and is given by the formula KE = (1/2) m*v^2, with m being the mass of the particle and
v being the velocity of the particle.

A body can have a
potential energy stored in it due to many causes some of which include potential energy
due to the gravitational force, the electromagnetic force and many
others.

Potential energy is converted to kinetic energy if
the body is given an opportunity. Like if the stretched band is released, all the
particles that make up the band accelerate and return to a neutral position where they
have zero potential energy.