The document discusses different types of energy: 1. Potential energy is stored energy that can be transformed into other forms of energy like kinetic energy. Potential energy exists due to an object's position or condition. 2. Gravitational potential energy is dependent on an object's mass, the acceleration of gravity, and its height. It is calculated as PE=mgh and measured in joules. 3. Elastic potential energy is the energy stored when an object like a rubber band or spring is stretched or compressed and can be released as the object returns to its original shape.