Can someone tell me what Energy [science] is?

Question

I need something long and nice to say for a movie!

Answer 1

The ability to do work

http://en.wikipedia.org/wiki/Energy

Answer 2

It is something that comes in many forms (such as light, sound, chemical, potential, kinetic, heat, etc.), it can change form, it is never really destroyed although it can be converted to mass in a nuclear reaction, and it has the ability to do work - that is it can cause other masses to be moved.