Newton and Joule

What is a Newton?

A Newton (N) is equal to the force that would give a mass of one kilogram an acceleration of one meter per second per second. So...

The force necessary to push an object of one kilogram of mass so that it accelerates one meter per second faster every second.

Ok...?

But we are using joules (J) to measure the energy an object has.

What is a Joule?

A force of 1 newton exerted over a distance of 1 meter.
or...
J = m²kgs^-2

Examples

To get an idea of how much energy a joule actually is, it helps to look at some everyday examples. 

A joule is the amount of energy needed to raise the temperature of 1 gram of cool, dry air by 1.0°C. An average person sitting quietly produces 100 J of heat every second. 

The amount of energy required to lift a small apple 1 meter against the Earth's gravity is roughly equivalent to 1 J.