What do you mean by 1 Joule of energy?

It a measure of any form of energy, including heat, in MKS units. That means the primative units are expressed in meters, kilograms, and seconds, namely kg*m^2/s^2. 1 Joule, for example, is the kinetic energy K of mass M=1 kilogram traveling at speed V = 1 meter per second, times 1/2. The 1/2 is there because K=(1/2)MV^2. For heat, a 1 Watt heat source running for 1 second will release 1 Joule of heat, since Watt is the MKS unit of power.

Define Joule

Heat is the amount of energy an object has within its atoms and molecules, arising from their vibration. The more heat they have, the more they vibrate. We measure heat by INDIRECTLY measuring the vibration of those molecules but 'at the end of the day', heat is about movement, even when it happens on such a tiny scale that you can't see it.

The definition of 1 joule is that it is the amount of energy needed to move 1kg of mass by 1metre... so this definition too is about movement.

The 'size' of one joule is entirely arbitrary.. if we had defined 1kg as being something other than what it is, then 1J would have been a different amount of energy. It is simply an amount of moving stuff from one place to another.. that we have agreed upon as a society. Once agreed, it then becomes a measure we can all use, because we all understand it to mean the same thing.

One joule is the work done, or energy expended, by a force of one newton moving one meter along the direction of the force. This quantity is also denoted as a newton metre with the symbol N·m.

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

1 joule is about the amount of energy it takes to lift an apple one meter against earths gravity

WHEN I JOULE OF WORK IS DONE

(mechanical work) and it generates the heat of i joule