Energy can mean various things:
- In physics, energy is a property of matter and space. It can be transferred between objects. It can be converted in its form. It cannot be created or destroyed.
- In economics it may mean the ‘energy industry’, as in fuel or electric power distribution.
- Energy can be used to heat, move or illuminate.
- In everyday use, the word is used to describe someone acting or speaking in a lively and vigorous way.