Public administration is, broadly speaking, the implementation of policy within a state framework. A good working definition is, "taking care of the state's, and international organizations', business by civil servants within the executive branch of government, other than public policy." Like law or medicine, but unlike economics and political science/politics, public administration is the term both for the subject matter and for the academic study of the same.
The more specific term public management refers to ordinary, routine or typical management concerns, but in the context of achieving public good with public infrastructure. There is necessarily some overlap between the terms.
See also: American Society for Public Administration
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