What is Category theory?
{{no sources|date=July 2024}} '''Category theory''' is a type of [[mathematics]]. Category theorists show how different ideas in mathematics are alike. For example, some ideas from [[topology]] and [[abstract algebra]] are similar. Ideas in category theory are written down in [[formulas]] or [[diagrams]]. Category theory can be used to make [[computer programs]] more secure or easy to write. A category is a mathematical object. It can be drawn with dots and arrows. Each arrow goes from one dot to one other dot. There can be many dots, sometimes so many that you cannot count them. An arrow is the abstract idea of a [[function]] and the dots are the [[domain]] and [[codomain]] of the function. Composition is a way to make a new arrow out of two arrows. If two arrows form an elbow shape, then they have a [[composition]] arrow from the start of the first to the end of the second. Composition obeys some [[axioms]], or equations. Many ideas in [[abstract algebra]] are examples of categories or can be used to make categories. Often, this makes the ideas seem more similar. {{math-stub}} [[Category:Fields of mathematics]]