The word category (from Greek κατηγορια meaning "assertion" or "accusation") has several meanings:

  • it is used informally to mean a class of things, as in "the category of all living things"
  • in philosophy:
    • Aristotle classified everything into 10 famous categories
    • others have tried the same, see categories of being
    • Kant uses the word for the preconceived notions we use to organize sense data
  • in mathematics:
    • a collection of mathematical objects of the same kind, together with the structure-preserving maps between them; as in "the category of all topological spaces and continuous maps". These are studied in category theory.
    • in topology, one distinguishes between sets of first and second category; see Baire space.

This is a disambiguation page, a page that just links to other pages for terms with multiple meanings. You might want to add more meanings for this term, or fix links on pages that link here to link directly to the subject pages.

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