Sociology of language is the study of the relations between language and society. It is closely related to the field of sociolinguistics, which focuses on the effect of society on language. One of its longest and most prolific proponents was Joshua Fishman, who among other major contributions, was founding editor of the International Journal of the Sociology of Language. Sociology of language studies society in relation to language whereas Sociolinguistics studies language in relation to society. For the former, society is the object of study, whereas, for the latter, language is the object of study. The basic idea is that language reflects, among several other things, attitudes that speakers want to exchange or that just get reflected through language use. These attitudes of the speakers is the sociologist's information.
A sociology of language would seek to understand the way that social dynamics are affected by individual and group language use. According to Su-Chiao Chen language is considered to be a social value within this field, which researches social groups for phenomenon like multilingualism and Lingual conflict. It would have to do with who is 'authorized' to use what language, with whom and under what conditions. It would have to do with how an individual or group identity is established by the language that they have available for them to use. It would seek to understand individual expression, one's (libidinal) investment in the linguistic tools that one has access to in order to bring oneself to other people.
Sociology of language, particularly American sociolinguistics, was regarded to have been founded in the early 1960s, mainly by William Labov, who developed much of the methodology.