Energy is a concept used in the natural sciences in general, is a property that allows any physical object to do some work. All transformations that can perceive the man of nature are the product of some kind of energy, the latter is the source of all movement. It is manifested with physical and chemical changes, such as an ice melting (physical) or the human digestive process (chemical). Energy is an abstract concept, that is, does not refer to a physical object is a mathematical tool to map the state of a physical system.
Isaac Newton is considered one of the greats of physics primarily by the contribution made on energy and were summarized in three laws of motion, inertia, force and action and reaction.
The unit of energy used by the international system is the Joule (J) in honor of the British physicist James Prescott Joule who was one of the first to prove that energy can become (after Newton).
In physics, the various types of movements are attributed to a type of energy, such as potential energy, kinetic, electromagnetic, among others. These are processing power to another type of energy, for example a bulb lit shortly begin to heat up, this means, as the vial undergoes the transformation of electrical energy into heat energy. Hence Newton's famous phrase "energy is not created or destroyed, only transformed"