The document discusses Chapter 3 of an organic chemistry textbook, which covers alkanes, their naming conventions, and stereochemistry. It introduces alkanes as unreactive compounds that are useful for demonstrating important organic chemistry concepts. The chapter also discusses functional groups, which are collections of atoms that determine a molecule's characteristic chemical behavior, such as double bonds in alkenes that react with bromine the same way. It provides examples of common functional groups including those containing multiple carbon-carbon bonds, carbon single-bonded to electronegative atoms, and carbon-oxygen double bonds.