This document discusses regional variations in language. It defines key terms related to language geography and variations, including standard language, dialects, accents, isoglosses, bidialectalism, bilingualism, diglossia, pidgins, and creoles. The standard language refers to the variety associated with education and administration regardless of region, while dialects are variations in vocabulary, grammar and pronunciation across regions. Accents also vary regionally but all speakers have accents. Isoglosses mark boundaries where linguistic features change between dialects.