Energy is a 'property' which you have when a force is applied over a certain distance. It's sort of counting up all the force which has acted on you, and giving a number you can use to make calculations simpler.
more accurately, energy is the potential to do work, but work is a function of force.
forces change the way things move. to make something move, change direction or stop moving, you need to exert a force on it. but you cannot exert a force unless you have the energy to do so.
when you move your mouse, your hand exerts a force on the mouse to move it. the energy required to exert that force comes from the energy stored in your muscles.
another example: think about bowling a ball at some skittles. when the ball is rolling, it has energy (kinetic energy), when it hits the skittles, it uses up that energy to exert a force on the skittles. the force knocks the skittles over. the movement of the ball gives it the energy to exert that force.
Originally posted by syano What is difference between energy and force? Is energy just a measurement of a force?
A big difference between the two is that force can be changed to much larger or smaller values by simple devices such as levers, screws, etc. But energy is a conserved quantity. So a given quantity of energy can be expended by applying a relatively large force over short distance, or smaller force over longer distance.
Also important: there is a "conservation of energy" law. There is no "conservation of force". In order to lift an object with weight 1 Newton a height of 1 meter, I MUST do 1Newton* 1 meter= 1 Joule of work. But if I use an inclined plane instead of lifting it straight up, I can reduce the force necessary.