Discourse: It is many ways of communication to let others know what human thinks or what human wants to explain:spoken languge written language and body language. the discourse happens though you are just thinking.
Critical discourse analysis: This emphasizes on how to reveal the real meaning to explain to audiences.
Sociolinguiatics: Is is language usage in socail context and trend. This can be deternmed the meaning in three points: 1)referential meaning, 2) socail status meaning and 3)Psychological meaning
Sociolinguiatic variables: They affect both his/her written discourse and readers; they are gender balance , age, level of education, dialect variation,and socail contexts and socail relationships.