A coup, short for coup d'état, is the sudden and illegal overthrow or alteration of an existing government by a small group, often involving the military or other elite factions. Unlike a revolution, which usually involves a large number of people seeking broader social or political change, a coup is a swift replacement of top government personnel without fundamentally changing a nation's social or economic policies. It typically involves control of all or part of the armed forces or police. Coups may be violent but can also occur without bloodshed, termed soft or bloodless coups. A self-coup occurs when a leader who came to power legally tries to stay in power through illegal means. In summary, a coup is a forceful and usually illegal seizure of authority from a government by a small group, often involving the military, aiming to replace the existing leadership abruptly.