(1) The process of restructuring a data model by reducing its relations to their simplest forms. It is a key step in the task of buildinga logical relational database design. Normalization helps avoid redundancies and inconsistencies in data. An entity is normalized if it meets a set of constraints for a particular normal form (first normal form, second normal form, and so on). See also denormalization, repeating group.
(2) The process of replacing surface form representations with their canonical form. This may include case normalization, where a capitalized word is replaced by a lowercase word: 'Run' becomes 'run'; grammatical normalization, where an inflected verb is replaced by the non-inflected form: 'runs' becomes 'run'; lexicographical normalization, where Unicode full-width characters is replaced with Unicode basic form, or white spaces are removed from Chinese text.
(3) The conversion of records that contain multivalued data from nonfirst-normal format (NF2) into one or more first normal format (1NF) rows.