Sociolinguistics analyzes the relationship between society, language use and linguistic structures. It focuses centrally on the ways in which language varies and describes how this variation characterizes geographic space (rural vs. urban, coast vs. highlands), social class, ethnicity, gender, generation (younger vs. older), and speech style (casual vs. formal). Some popular subdisciplines within sociolinguistics are discourse analysis (the study of how speakers use language in social interaction), language contact (the study of contexts where two or more languages are normally used and the ways bilingual speakers use them), language and gender (analysis of the differences between ‘male’ and ‘female’ ways of communicating), and language attitudes (observation of speakers’ ideas about what constitutes ‘good’ and ‘bad’ or ‘correct’ and ‘incorrect’ language).
 

Applied Linguistics includes studies of first and second language acquisition (how people learn to express themselves through language—both spoken and written—and use it in context), language pedagogy (the design and analysis of methods used to teach people languages, both native and nonnative), the editing of dictionaries and formal grammars, translation and interpretation, and language policy and planning (the implementation and analysis of laws and policies around societal language use and language education). 
 

Psycholinguistics addresses the basic relationships between psychology, language and cognition.
 

Neurolinguistics explores physiological aspects of the brain in connection with human language capacity.
 

Computational linguistics applies theories of linguistics to the design of artificial (computer) language and computerized language technologies.