The following
outline is provided as an overview of and guide to
category theory, the area of study in
mathematics that examines in an
abstract way the properties of particular mathematical concepts, by formalising them as collections of
objects and
arrows (also called
morphisms, although this term also has a specific, non category-theoretical sense), where these collections satisfy certain basic conditions. Many significant areas of mathematics can be formalised as categories, and the use of category theory allows many intricate and subtle mathematical results in these fields to be stated, and proved, in a much simpler way than without the use of categories.