Public administration involves the implementation of government policies and operations, including planning, organizing, directing, coordinating, and controlling government work. It has evolved over time from focusing on separating politics and administration, to emphasizing principles of administration and efficiency, to considering human factors and incorporating other social sciences. Public administration is significant as the key instrument of government to maintain order and protect citizens. It also enables development, supports modern welfare states by providing public services, and is an important subject of academic study.