The Oxford English Dictionary defines power in several ways:

•  Generally speaking, as an ability, capacity.

•  Ability to act or affect something strongly; physical or mental strength; might; vigour, energy; effectiveness.

•  Political or national strength.

•  Control or authority over others; dominion, rule; government, command, sway.

•  Capacity to direct or influence the behaviour of others; personal or social influence

•  Legal ability, capacity or authority to act; delegated authority; authorization, commission; legal authority vested in a person or persons in a particular capacity.

In Cultural Studies power is almost a synonym for culture as we saw in the introductory lectures: