categorie

Categorie is a fundamental concept used to group items that share properties or functions. It provides a way to organize knowledge and help comparisons, retrieval, and reasoning. The term comes from Latin categoria, via Greek katēgoria, and in French is catégorie; in many languages the corresponding term is the direct cognate. A category designates both a class of things and the criteria that define membership in that class.

In biology, categories form a hierarchical taxonomy such as species, genus, and family, used to classify living organisms by shared characteristics, ancestry, and evolutionary relationships. In linguistics and cognitive science, semantic categories group words and concepts into classes like colors, kinship terms, or actions, aiding comprehension and processing.

In mathematics, there are two related ideas. A simple notion uses categories as collections of objects and arrows. Category theory, a more advanced framework, studies categories and morphisms between them, with composition and identities, enabling abstraction across algebra, topology, and logic.

In statistics and data science, categories describe qualitative variables whose values are drawn from a finite set, such as gender or product type, often encoded for analysis. In information science, categorization or taxonomy assigns items to categories to improve search, organization, and interoperability; ontologies formalize the relationships among categories.

Ambiguities can arise when boundaries are not well defined, and categories may evolve over time as knowledge changes. See also taxonomy, ontology, category theory, set theory, data classification.