This document discusses the topic of dialectology, which is the scientific study of linguistic dialects. It defines dialect as a specific form of a language that is peculiar to a certain region or social group. Dialectology studies variations in language based on geographic distribution and associated features. To distinguish between dialects of the same language, speakers must be able to understand each other. The document outlines levels of dialect analysis including geography, ethnicity, and social class. It also discusses the need to study dialects from both linguistic and social perspectives.