CONSERVATION OF ENERGY PRINCIPLE
There are many different types of energy but they all follow this same principle:
ENERGY CAN BE TRANSFERRED USEFULLY FROM ONE FROM TO ANOTHER, STORED OR DISSIPATED - BUT IT CAN NEVER BE CREATED OR DESTROYED! NEVER.
Disipated - fancy way of saying the energy is spread out AND lost.
ENERGY IS ONLY USEFUL WHEN IT CAN BE CONVERTED FROM ONE FORM TO ANOTHER.
DONT FORGET THIS!