Public opinion is the aggregate of individual attitudes or beliefs held by the adult population. Public opinion can also be defined as the complex collection of opinions of many different people and the sum of all their views.

The principle approaches to the study of public opinion may be divided into 4 categories:

Public opinion as a concept gained credence with the rise of "public" in the eighteenth century. The English term "public opinion" dates back to the eighteenth century and has derived from the French l’opinion, which was first used in 1588 by [Montaigne]Donsbach, Wolfgang. The International Encyclopedia of Communication. Wiley-Blackwell, 2008. This concept came about through the process of [urbanization] and other political and social forces. For the first time, it became important what people thought, as forms of political contention changed.

Adam Smith, one of the earliest classical economists, refers to public opinion in his Theory of Moral Sentiments, but it was Jeremy Bentham, the famous utilitarian Philosopher, who fully developed theories of public opinion. He opined that public opinion had the power to ensure that rulers would rule for the greatest happiness of the greater number. He brought in Utilitarian philosophy in order to define theories of public opinion. The German sociologist Ferdinand Tönnies, by using the conceptional tools of his theory of Gemeinschaft and Gesellschaft, argued (1922, "Kritik der öffentlichen Meinung"), that 'public opinion' has the equivalent[social function] in societies (Gesellschaften) which religion has in communities (Gemeinschaften). Rolf Fechner/Lars Clausen/Arno Bammé (eds.): Öffentliche Meinung zwischen neuer Religion und neuer Wissenschaft. Ferdinand Tönnies' „Kritik der öffentlichen Meinung“ in der internationalen Diskussion, in: Tönnies im Gespräch, tom. 3, Munich/Vienna: Profil 2005, ISBN 3-89019-590-3.</ref>