Defined in broadest terms, public administration consists of all those operations having for their purpose the fulfillment or enforcement of public policy. This definition covers a multitude of particular operations in many fields — the delivery of a letter, the sale of public land, the negotiation of a treaty, the award of compensation to an injured workman, the quarantine of a sick child, the removal of litter from a park, manufacturing plutonium, and licensing the use of atomic energy. It includes military as well as civil affairs, much of the work of courts, and all the special fields of government activity— police, education, health, construction of public works, conservation, social security, and many others.
Leonard D. White, Introduction to the Study of Public Administration, 1926. p. 1