Weber defined power as the ability to force or coerce someone, despite not agree, then your will because of your position or your strength. Many managers use their power, establishing penalties for not meeting targets set responsibilities and people under their charge, which makes officials do their homework rather than fearing involvement, belief or taste. In time, Weber defines authority as the art of getting people to do voluntarily what you want because of your personal influence. The authority is to get people to do the will of the manager on a voluntary basis, ie because they have been asked to do so and not because they are promised, but they do. It is important to emphasize that power is defined as a power, while authority is defined as an art.
The exercise of power requires no intelligence, skill or courage, just as there is merit in the management. However, displaying a level of authority over people requires the development and implementation of additional skills. It may be in a position of power in an organization and have no authority, and vice versa. You can have power by virtue of occupying a high position, to inherit much money or have many influential acquaintances, this does not apply to the authority. The authority has to do with what you are as a person, with your character and the influence that has been built on people. A manager must build your authority if you want to keep medium and long within a synergistic team and motivated.