That shortened definition comes from Max Weber. A more accurate translation from the original German is:
“Power is the probability that one actor within a social relationship will be in a position to carry out his own will despite resistance.”
Weber distinguished power from authority. Power is the ability to impose one’s will; authority is power that is perceived as legitimate and therefore obeyed without constant force. This distinction explains why modern institutions rely less on coercion and more on rules, offices, and procedures—and why obedience can feel responsible even when judgment is no longer engaged.