Energy is a key aspect of life on earth. We use energy to do work. Energy lights our cities. Energy powers our cars, trains, planes and rockets. Energy warms our homes, cooks our food, and gives us pictures on television. Energy powers machinery in factories and tractors on a farm.

Energy from the sun gives us light during the day. It dries our clothes when they're hanging outside on a clothes line. It helps plants grow. Energy stored in plants is eaten by animals, giving them energy. And predator animals eat their prey, which gives the predator animal energy.

Everything we do is connected to energy in one form or another.

Energy is defined as: "the ability to do work."

Work means moving something, lifting something, warming something, lighting something. All these are various types of work. But where does energy come from?

On these pages, many sources of energy are explained via visual examples. To view such examples, you must have the Flash plug-in installed on your computer. The following types of energy animations will be covered:

Mechanical
Gravitational
Nuclear
Spring
Light
Chemical
Kinetic