In semantics, discourses are linguistic units composed of several sentences - in other words, conversations, arguments or speeches. Conventional phraseology often characterises a discourse as 'learned', as in: 'The Professor delivered a learned discourse on the obscure art of Lobster spotting.'

Discourse analysis is the study of language used by members of a speech community. It looks at both language form and language function and includes the study of both spoken interaction and written texts. It identifies linguistic features that characterize different genres as well as social and cultural factors that aid in our interpretation and understanding of different texts and types of talk. An analysis of written texts might include a study of topic development and cohesion across the sentences, while an analysis of spoken language might focus on these aspects plus turn-taking practices, opening and closing sequences of social encounters, or narrative structure.

Discourse analysis originally developed from a variety of disciplines: sociolinguistics, anthropology, sociology, and social psychology. Thus discourse analysis takes different theoretical perspectives and analytic approaches (among others):

• Speech act theory
• Interactional sociolinguistics
• Ethnography of communication
• Pragmatics
• Conversation analysis
• Variation analysis

Although each approach emphasizes different aspects of language use, they all view language as social interaction.

In the social sciences, a discourse is considered to be an institutionalized way of thinking, a social boundary defining what can be said about a specific topic. Discourses are seen to affect our views on all things; in other words, it is not possible to escape discourse. For example, two distinctly different discourses can be used about various guerrilla movements describing them either as "freedom fighters" or "terrorists". In other words, the chosen discourse delivers the vocabulary, expressions and perhaps also the style needed to communicate.

Discourse is closely linked to different theories of power and state, at least as long as defining discourses is seen to mean defining reality itself.

The social conception of discourse is often linked with the work of the French social philosopher Michel Foucault (1926-1984).