In public relations and communication science, publics are groups of individual people, and the public (a.k.a. the general public) is the totality of such groupings. This is a different concept to the sociological concept of the Öffentlichkeit or public sphere. The concept of a public has also been defined in political science, psychology, marketing, and advertising. In public relations and communication science, it is one of the more ambiguous concepts in the field. Although it has definitions in the theory of the field that have been formulated from the early 20th century onwards, it has suffered in more recent years from being blurred, as a result of conflation of the idea of a public with the notions of audience, market segment, community, constituency, and stakeholder.
Public Administration is the implementation of government policy and also an academic discipline that studies this implementation and prepares civil servants for working in the public service. As a "field of inquiry with a diverse scope" whose fundamental goal is to "advance management and policies so that government can function". Some of the various definitions which have been offered for the term are: "the management of public programs"; the "translation of politics into the reality that citizens see every day"; and "the study of government decision making, the analysis of the policies themselves, the various inputs that have produced them, and the inputs necessary to produce alternative policies."
Liberty and good government do not exclude each other; and there are excellent reasons why they should go together. Liberty is not a means to a higher political end. It is itself the highest political end. It is not for the sake of a good public administration that it is required, but for security in the pursuit of the highest objects of civil society, and of private life.
John Dalberg-Acton, 1st Baron Acton, The History of Freedom in Antiquity (1877)
Weber's wide-ranging contributions gave critical impetus to the birth of new academic disciplines such as sociology and public administration as well as to the significant reorientation in law, economics, political science, and religious studies.
Sung Ho Kim, "Max Weber", The Stanford Encyclopedia of Philosophy (Fall 2012 Edition), Edward N. Zalta (ed.)
Public administration is a process or a theory, not merely an accumulation of detailed facts. It is Verwaltungslehre. The object of administrative study should be to discover, first, what government can properly and successfully do, and secondly, how it can do these proper things with the utmost possible efficiency and at the least possible cost both of money and of energy.
Marshall E. Dimock, "The Study of Administration." American Political Science Review 31.01 (1937): p. 29