In physics, a force is said to do work when it acts on a body when there is a displacement of the point of application in the direction of the force. The force does not need to cause the displacement. For example, when you lift a suitcase from the floor, there are two forces that do work: the normal force by your hand and the gravitational force.
The term work was introduced in 1826 by the French mathematician Gaspard-Gustave Coriolis as “weight lifted through a height”, which is based on the use of early steam engines to lift buckets of water out of flooded ore mines. The SI unit of work is the newton-metre or joule (J).
The work done by a constant force of magnitude F on a point that moves a displacement d in the direction of the force is the product,
W = Fd.
For example, if a force of 10 newton (F = 10 N) acts along a point that travels 2 metres (d = 2 m), then it does the work W = (10 N)(2 m) = 20 N m = 20 J. This is approximately the work done lifting a 1 kg weight from ground to over a person’s head against the force of gravity. Notice that the work is doubled either by lifting twice the weight the same distance or by lifting the same weight twice the distance.
Source (Read More): http://en.wikipedia.org/wiki/Work_%28physics%29
A productive perspective to consider.