The ability to do work and make things happen is known as energy. You may not always be aware of it but you use energy in your daily activities. You would not be able to do a lot of the things you do now without energy. You use light energy to see things. Sound energy enables you to hear the different sounds around you. And heat energy keeps you warm. Light, sound, and heat energies are just three of the kinds of energy that you experience every day.

The sun is the most important source of light and heat on Earth. Its energy helps plants to produce their own food, allows people and animals to see and enjoy the beauty of the world, and provides people and animals with vitamin D that makes their bones and skin healthy.