What does Foucault mean by discursive practices or discursive constitutions in definition of discourse?
Foucault uses the concept of discursive practices or discursive constitutions in the definition of discourse.
What does he mean by this concept? How are discursive practices different from discourses?
A discursive practice in foucauldian terms is "the process through which [dominant] reality comes into being". This is a very nebulous process, of course, and Foucault focuses on questions of power. His notions of 'governmentality' and 'biopower', from his later work, are helpful to understand this. Foucault does not only focus on formal and semi-formal institutions like the state, the law, schools, clinics, prisons, the family, race, gender, and sexuality, or not just on what the critical theorists and neo-marxists call the 'Culture Industry' (like the media); he notoriously concerned with how power is inscribed on the body, at the level of people's movement and perception of themselves. How does Power produce 'docile bodies'? is another way in which he poses the question. Biopower in this sense refers to the capillary living network (like veins or hairs) of how Power is propagated and inscribed on docile bodies.
By discursive practices Foucault means power relations in the society;how is a relationship created by asserting power through the use of language.Language of the powerful is shown through a variety of techniques such as speech styles which include vocabulary,syntax intonation,proverbs,naming strategies etc.Power and resistance are inter linked.The discursive practices denote the social status of the speakers thus bringing social stratification.
Discourse is the collection of hegemonic accepted norms of any given period (or Episteme in Foucault's archeological work, pre Discipline and Punish after which Foucault began using genealogy to delineate social change, but that's another question!). In simple terms, discourse has mores or acceptable behaviors according to the discourse of the era. As discourse is constantly in flux, hegemonic acceptable norms are too. Discursive practices are the way in which discourse brings these hegemonic norms into life and are usually determined within the power/knowledge dichotomy.