classification

(noun) the act of distributing things into classes or categories of the same type. Synonyms: categorization, categorisation, compartmentalization, compartmentalisation, assortment.

(noun) a group of people or things arranged by class or category. Synonyms: categorization, categorisation.

(noun) the basic cognitive process of arranging into classes or categories. Synonyms: categorization, categorisation, sorting.

(noun) restriction imposed by the government on documents or weapons that are available only to certain authorized people.