Definition of Energy
Energy is the ability to do work. In other words, energy produces change in something---it can do things for us.
![People Jumping](http://www.ei.lehigh.edu/learners/energy/basics/personJump2.jpg)
Energy enables people to walk, run, and jump.
![Car Driving](http://www.ei.lehigh.edu/learners/energy/basics/carMotion.jpg)
Energy allows cars, planes, and motor boats to go.
![Cell Phone](http://www.ei.lehigh.edu/learners/energy/basics/handPhone.jpg)
Energy permits a cell phone, light bulb, or television to be turned on.