Library classification is the arrangement of library holdings in a logical order, from the general to the specific, based on the main subject of the resources. The general steps of classifying books are presented in the chapter and the main classification schemes and a few localized or discipline-oriented systems are listed. The text continues by analysing the main types of classification systems, i.e. hierarchical, enumerative, faceted and analytico-synthetic. The major classification schemes are then reviewed and the chapter ends by discussing the criteria for selecting a classification scheme.