This page will focus on the topic of Power:

Power- is the rate (energy amount per time period) at which work is done or energy converted.

Work is a quantity concerned with a force over a certain displacement, but it has nothing to do with the amount of time with  which this force acts over. At times this work is done very quickly and at times it is done much more slowly. For example take two people; a rock climber and a trail hiker. A rock climber takes a much longer amount of time to raise themselves a few metres up alongside the side of a mountain; where as compared to a trail climber (who chooses the easier path up the  mountain) they might elevate themselves the same amount of metres in a much shorter period of time. The two people might do the same amount of work, yet the hiker does the work in considerably less time than the rock climber. The quantity that has to do with the rate at which a certain amount of work is done is known as the power. The hiker has a greater power rating than the rock climber. Power is the rate at which work is done. It is the work/time ratio: 

Power = Work / time or P = W / t

The SI unit for power is the Watt (W). A Watt is equivalent to a Joule/second. For historical reasons, the horsepower is occasionally used to describe the power delivered by a machine. One horsepower is equivalent to approximately 750 Watts. An alternative equation for power: