Political and social power involves the exercise of social resources to compel various kinds of unwilling behavior by others. What creates power in society? What are the sorts of social and structural factors that permit individuals to exercise power? And what features of personality lead a given individual to choose to use the instruments of power to achieve his/her will? In short -- how does power pertain to "structure" and "agency"?
This is one of the categories in social analysis that requires that we bring together both agency and structure. Individuals wield power; but they only do so on the basis of resources and advantages that are conferred upon them by existing social relations. The enduring social relations that exist in a society -- for example, property relations, administrative and political relations, or the legal system -- constitute a structure within which agents act, and they determine the distribution of crucial social resources that become the raw materials on the basis of which agents exercise power over other individuals and groups. So the particular details of a social structure are crucial in determining the forms of power that exist in the society. For example, a privileged position within the property system -- the possession of significant income and wealth -- confers a resource advantage on people in that position. They can use their wealth to solicit powerful allies; they can purchase media outlets; they can influence politicians -- all with an eye to achieving their goals in spite of the contrary wishes or interests of others.
Likewise, a privileged position in the communications system -- a television news producer or newspaper publisher, for example -- can use his/her position to alter the way in which stories are presented in such a way as to change the way the public thinks about the issues; and these changes in thought can lead to changes in behavior. And an elected official can exercise power by setting the agenda for others -- by including or excluding various options from consideration.
So one's position within these various social structures -- systems of social relations -- determines the volume of social resources upon which one can call in the effort to constrain or compel the actions of others. Position determines one's capacity for power. But it does not determine the exercise of power. To be said to exercise power, it is necessary to have the goal of compelling people to do things they don't want to do. This is where agency or the "will to power" comes in. It is possible for a person with access to great power resources to nonetheless behave in ways that do not make use of power but rather depend on building consent and consensus. We might contrast Churchill with Stalin in mobilizing society for war; Churchill persuaded the British people to sacrifice in support of the war effort, whereas Stalin used the coercive power of the state to achieve his war mobilization goals.
This fact suggests that we need to consider something of the psychology of power. This is a topic that Adorno and other critical theorists invoked through the concept of the "authoritarian personality" -- an idea invoked largely in an effort to understand fascism. Others might attempt to assimilate the willingness to use power under the category of "opportunistic" or "instrumentalist" decision-making: coercion is considered as simply one out a menu of feasible strategies for achieving one's will. (This is perhaps the foundation of Hobbes's understanding of the pursuit and use of power.) And here we might speculate that the "democratic personality" is a set of dispositions to behavior that lead the agent to seek out persuasion and consensus rather than force, deception, and coercion as instruments through which to achieve one's goals. (Taken to the limit, we might say that a proper democracy creates an environment in which there is neither opportunity nor impulse towards the exercise of power.)
On this way of laying out the landscape of power, there are several dimensions to be considered: the social arrangements that make it possible for some individuals to pressure, coerce, and compel other individuals to do their bidding; the social arrangements that create profound conflicts of interest in the context of which the incentive to wield power naturally arises; and the circumstances of social psychology and personality that lead some individuals to choose to make use of resources of power to coerce, while others choose strategies that depend on willing consent to achieve collective purposes.