The document discusses sociolinguistics and language variation. It defines sociolinguistics as the systematic study of language in society, focusing on how individuals and groups use language in social contexts. There are three main perspectives in sociolinguistics: geographic, examining regional dialects; anthropological, studying the relationship between language, culture and thought; and sociological, analyzing the link between social relations and language varieties. Speech communities are groups that share the same or similar language varieties. Varieties include dialects, sociolects, and idiolects, which differ by region, social class, gender, age, and ethnicity at the lexical, phonological and syntactic levels. Pidgins are simplified mixed languages for basic communication between