It is the study of the effect of any and all aspects of society, including cultural norms, expectations, and context, on the way language is used, and the effects of language use on society. Sociolinguistics differs from sociology of language in that the focus of sociolinguistics is the effect of the society on the language, while the latter's focus is on the language's effect on the society. Sociolinguistics overlaps to a considerable degree with pragmatics. It is historically closely related to linguistic anthropology and the distinction between the two fields has even been questioned recently.
Supplemental catalog subcollection information: The Rosetta Project; Language and Linguistics