Without energy in our bodies, we wouldn't be able to do anything. We couldn't walk, talk, or even play. Energy is usable power. And energy is related to some kind of motion.
All living things need energy, no matter what they do. Plants get their energy from sunlight. This energy is stored indifferent chemicals（化合物)inside the plant.
Animals that eat plants take the energy stored in the plants. The energy is then stored in chemicals inside the animals as "food energy". The same happens when animals eat other animals.
Plants and animals use energy every day as they grow and do the work of being a plant or an animal. So plants have to keep absorbing(吸收)sunlight, and animals have to keep eating plants or other animals.
It isn't only living things that have energy. A dead tree has hidden energy. When we burn its wood, it gives off warmth, or "heat energy". The Sun too makes heat energy as it keeps burning.
The Sun gives off not just heat but also light, as "light energy". A battery in a flashlight makes it shine, generating light energy. But if we put the same battery in a radio, we get music. A battery's energy is known as "electrical energy". And in a toy car that electrical energy produces movement.
If we couldn't use heat, light, or electrical energy, we couldn't drive cars or cook food. We wouldn't have light at night time.
