Next to thematic coding, NVivo also allows coding with classifications. Classifications can be considered as a separate database in a project. In such a database, NVivo stores variables (called Attributes) that allow comparisons. Even though the classification tool is programmed in a relatively uniform way in the program, NVivo distinguishes between two types of classifications: file classifications and case classifications. Both types are explained, and their use is shown with analytical examples. Given the extended use of case classifications, the chapter elaborates on creating (twin) cases and storing data inside cases to make comparisons at a later stage possible. The chapter ends with tips on gaining efficiency in using classifications by showing how Excel tables (descriptive matrices) can be converted to classifications, avoiding all preparatory work being done manually.