Kinetic, potential, thermal, chemical, electrical, electrochemical, electromagnetic and nuclear energy are the different forms of energy. Each energy form measures the ability of an object to do work on another object. Each energy form is a way that an object possesses energy.
Kinetic energy refers to an object or system in motion. For example, a ball flying through the air possesses kinetic energy. Potential energy is an object's potential to turn into kinetic energy. A book sitting on a table has potential energy because it could fall off the table. Thermal energy is related to the temperature of a system. The higher temperature results in an increase in potential and kinetic energy.
Chemical energy is a form of microscopic potential energy. For example, glucose reacting with oxygen releases energy. Electrical energy produces electric currents that can be transferred from one system to another. Electrochemical energy is electric energy that can be stored in a chemical way. A car battery is an example of an electrochemical energy source. Electromagnetic energy is light energy. The sun transmits light to the Earth through radiation. Nuclear energy is a source of energy that involves a change in the structure of the nuclei of atoms.