| Term | Definition |
| Energy | The ability to do work or cause change. |
| Kinetic energy | Energy that an object has due to its motion. |
| Potential energy | Energy that is stored and held in readiness. |
| Elastic potential energy | The energy of stretched or compressed objects. |
| Gravitational potential energy | Potential energy that depends on the height of an object. |
| Mechanical energy | Kinetic or potential energy associated with the motion or position of an object. |
| Thermal energy | The total energy of the particles in an object. |
| Chemical energy | The potential energy stored in chemical bonds. |
| Electrical energy | The energy of moving electric charges. |
| Electromagnetic energy | energy of light and others forms of radiation. |
| Nuclear energy | The potential energy stored in the nucleus of an atom. |
| Energy conversion | The process of changing one form of energy into another. |
| Law of conservation of energy | The rule that energy cannot be created or destroyed. |
| Fossil fuels | Materials such as coal that are burned to release their chemical energy. |
| Power | The rate at which the work is done. |