From Wikipedia on 12-Sep-2014
In social science and politics, power is the ability to influence or control the behavior of people. The term authority is often used for power perceived as legitimate by the social structure. Power can be seen as evil or unjust, but the exercise of power is accepted as endemic to humans as social beings. In the corporate environment, power is often expressed as upward or downward. With downward power, a company’s superior influences subordinates. When a company exerts upward power, it is the subordinates who influence the decisions of the leader.
The use of power need not involve coercion (force or the threat of force). At one extreme, it more closely resembles what everyday English-speakers call influence, although some authors make a distinction between power and influence – the means by which power is used.