Simply put, energy is the ability to a cause change. Energy can cause many types of change. Think about when you have a lot of energy. You are able to do a lot of things. When you dont have a lot of energy, you may sit around and do very little. A similar thing happens to particles of matter as energy is added. The more energy there is, the faster the particles of matter move. Energy is also the reason you are able to move around. In fact, matter is always in motion. It can even change from one form to another. For example, electrical energy can be converted into heat energy. You see this every time you use the toaster. Energy causes a change in matter when you lift your arm. Energy can be used to move matter. You use energy to take a step to move forward. Thanks to energy, your body moves. The energy of moving matter is called kinetic energy. 
Lifting your arm, walking and moving around are all forms of what type of energy?
Heat energy