Monoid

A monoid is a basic concept in mathematics and computer science that describes a set of elements combined with an operation that has two key properties: it is associative (changing the grouping doesn't affect the result) and there is an identity element (a special element that, when combined with any other, leaves it unchanged). For example, the set of natural numbers with addition is a monoid: zero is the identity, and adding numbers doesn't depend on how you group them. Monoids help structure and understand how different elements combine in consistent, predictable ways.