Practice theory (or Praxeology, Theory of Social Practices) is a theory (or 'family' of theories) which seeks to understand and explain the social and cultural world by analyzing the basic bodily, knowledge based practices that interconnect to form more complex social entities like groups, lifestyles, social fields or entire societies. Practice theory, as outlined by Sherry Ortner, "seeks to explain the relationship(s) that obtain between human action, on the one hand, and some global entity which we call 'the system's on the other". The approach seeks to resolve the conflict in classical social theory between collectivist structuralist approaches and individualist action theories which attempted to explain all social phenomena in terms of intentional individual actions.
Practice theory is strongly associated with the French theorist and sociologist Pierre Bourdieu. His concept of habitus represents an important formulation of the principles of practice theory. Bourdieu developed the notion of 'habitus' to capture 'the permanent internalisation of the social order in the human body'. His book, Outline of a Theory of Practice, which is based on his work in Algeria during the Algerian War of Independence is an example of Bourdieu's formulation of practice theory applied to empirical data gathered through ethnography. Several works of his are considered classics, not only in sociology, but also in anthropology, education, international relations and cultural studies. Distinction: A Social Critique of the Judgement of Taste (La Distinction) was named as one of the 20th century's ten most important works of sociology by the International Sociological Association.
Known for his theory of structuration and his holistic view of modern societies, Anthony Giddens is considered to be one of the most prominent modern sociologists. His works, Central Problems in Social Theory (1979) and The Constitution of Society (1984), brought him international fame on the sociological arena. Giddens developed the theory of structuration, an analysis of agency and structure, in which primacy is granted to neither, to demonstrate 'how principles of order could both produce and be reproduced at the level of practice itself' and not through some 'ordering' society impinging upon individual actors from above.
A closely related notion to Bourdieu's habitus is Michel Foucault's concept of 'discipline'. Like habitus, discipline 'is structure and power that have been impressed on the body forming permanent dispositions'. In contrast to Bourdieu, though, Foucault laid particular emphasis on the violence through which modern regimes (e.g. prisons and asylums) are used as a form of social control.
Theodore Schatzki developed an alternative theory of practice, primarily in his books Social Practices (1996) and The Site of the Social (2002). His basic premise, derived from Martin Heidegger and Ludwig Wittgenstein, is that people do what makes sense for them to do. Practices make up people's 'horizon of intelligibility'. In Schatzki's work, practices are defined as 'open-ended spatial-temporal manifolds of actions' (Schatzki, 2005, p. 471) and also as 'sets of hierarchally organized doings/sayings, tasks and projects'  Moreover, practices consist of four main elements: (1) practical understanding - "knowing how to X, knowing how to identify X-ings, and knowing how to prompt as well as respond to X-ings" (idem, p. 77); (2) rules - "explicit formulations, principles, precepts, and instructions that enjoin, direct or remonstrate people to perform specific actions" (idem, p. 79); (3) teleo-affective structure - "a range of normativized and hierarchically ordered ends, projects and tasks, to varying degrees allied with normativized emotions and even mood" (idem, p. 80); and (4) general understanding.
Agency: An actor choosing to act, the human ability to act upon and change the world.
Field: A structured social space with its own rules, schemes of domination, legitimate opinions. Bourdieu uses the concept of field instead of analyzing societies solely in terms of classes. For example, fields in modern societies include arts, education, politics, law and economy.
Habitus: Collective system of dispositions that individuals or groups have. Bourdieu uses habitus as a central idea in analyzing structure embodied within human practice. The notion captures 'the permanent internalization of the social order in the human body'.
Doxa: Those deeply internalised societal or field-specific presuppositions that 'go without saying' and are not up for negotiation. A constructed vision of reality so naturalized that it appears to be the only vision of reality learned, fundamental, deep-founded, unconscious beliefs, and values, taken as self-evident universals, that inform an agent's actions and thoughts within a particular field, e.g. 365 days, 24hrs, 60 seconds.
Hexis: The way in which social agents 'carry themselves' in the world; their gait, gesture, postures, accent etc.
Cultural capital: Assets which enable holders to mobilize cultural authority e.g., competencies, education, intellect, style of speech, dress, or physical appearance.
Structuralism: A theoretical paradigm that privileges social structure over social action, Elements of human culture must be understood in terms of their relationship to a larger, overarching system or structure. According to structural theory in anthropology and social anthropology, meaning is produced and reproduced within a culture through various practices, phenomena and activities that serve as systems of signification. A structuralist approach may study activities as diverse as food-preparation and serving rituals, religious rites, games, literary and non-literary texts, and other forms of entertainment to discover the deep structures (e.g. mythology, kinship) by which meaning is produced and reproduced within the culture.
Structuration: Human agency and social structure are intertwined. Praxis is the repetition of the acts of individual agents which reproduces or subverts the social structure. Social life is more than random individual acts, but is not merely determined by social forces. There is a social structure - traditions, institutions, moral codes, and established ways of doing things; but it also means that these can be changed when people start to ignore them, replace them, or reproduce them differently.