Sociologists usually define power as the ability to impose one's will on others, even if those others resist in some way.
- "By power is meant that opportunity existing within a social relationship which permits one to carry out one's own will even against resistance and regardless of the basis on which this opportunity rests."
- Max Weber, Basic Concepts in Sociology
"Power" in the sociological sense subsumes both physical power and political power. In some ways it more closely resembles what everyday English-speakers call "influence".
More generally, one could define "power" as the more or less unilateral ability (real or perceived) or potential to bring about significant change, usually in people's lives, through the actions of oneself or of others.
The exercise of power and the attempt to gain more power seem endemic to humans as social and gregarious beings.
Power manifests itself in a relational manner: one cannot meaningfully say that a particular person "has power" without also specifying the other parties to the social relationship.