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.

The name "public" originates with the Latin "populus" or "poplicus", and in general denotes some mass population ("the people") in association with some matter of common interest. So in political science and history, a public is a population of individuals in association with civic affairs, or affairs of office or state. In social psychology, marketing, and public relations, a public has a more situational definition. John Dewey defined (Dewey 1927) a public as a group of people who, in facing a similar problem, recognize it and organize themselves to address it. Dewey's definition of a public is thus situational: people organized about a situation. Built upon this situational definition of a public is the situational theory of publics by James E. Grunig (Grunig 1983), which talks of nonpublics (who have no problem), latent publics (who have a problem), aware publics (who recognize that they have a problem), and active publics (who do something about their problem).

In public relations and communication theory, a public is distinct from a stakeholder or a market. A public is a subset of the set of stakeholders for an organization, that comprises those people concerned with a specific issue. Whilst a market has an exchange relationship with an organization, and is usually a passive entity that is created by the organization, a public does not necessarily have an exchange relationship, and is both self-creating and self-organizing. Publics are targeted by public relations efforts. In this, target publics are those publics whose involvement is necessary for achieving organization goals; intervening publics are opinion formers and mediators, who pass information to the target publics; and influentials are publics that the target publics turn to for consultation, whose value judgements are influential upon how a target public will judge any public relations material.

Public relations theory perspectives on publics are situational, per Dewey and Grunig; mass, where a public is simply viewed as a population of individuals; agenda-building, where a public is viewed as a condition of political involvement that is not transitory; and "homo narrans", where a public is (in the words of Gabriel M. Vasquez, assistant Professor in the School of Communication at the University of Houston) a collection of "individuals that develop a group consciousness around a problematic situation and act to solve the problematic situation" (Vasquez 1993, pp. 209)

One non-situational concept of a public is that of Kirk Hallahan, professor at Colorado State University, who defines a public as "a group of people who relate to an organization, who demonstrate varying degrees of activity—passivity, and who might (or might not) interact with others concerning their relationship with the organization".

Famous quotes containing the word public:

    Chippenhook was the home of Judge Theophilus Harrington, known for his trenchant reply to an irate slave-owner in a runaway slave case. Judge Harrington declared that the owner’s claim to the slave was defective. The owner indignantly demanded to know what was lacking in his legally sound claim. The Judge exploded, ‘A bill of sale, sir, from God Almighty!’
    —For the State of Vermont, U.S. public relief program (1935-1943)

    Utah is the only State that gives condemned men a choice between death by hanging or before a firing squad. Most prisoners prefer the firing squad, but one obstinate convict in 1912 elected to be hanged because “hanging is more expensive to the state.”
    State of Utah, U.S. public relief program (1935-1943)

    A ‘spasm band’ is a miscellaneous collection of a soap box, tin cans, pan tops, nails, drumsticks, and little Negro boys. When mixed in the proper proportions this results in the wildest shuffle dancing, accompanied by a bumping rhythm.
    —For the City of New Orleans, U.S. public relief program (1935-1943)