A monad is a monoid in the category of endofunctors. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws, specifically unit and multiplication operations analogous to a monoid's identity and binary operation. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws, specifically unit and multiplication operations analogous to a monoid's identity and binary operation, allowing us to sequence computations while abstracting away their underlying complexity. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws, specifically unit and multiplication operations analogous to a monoid's identity and binary operation, allowing us to sequence computations while abstracting away their underlying complexity and systematically managing effects in pure functional programming languages. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws, specifically unit and multiplication operations analogous to a monoid's identity and binary operation, allowing us to sequence computations while abstracting away their underlying complexity. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws, specifically unit and multiplication operations analogous to a monoid's identity and binary operation. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps of a category with operations that satisfy certain laws. A monad is a monoid in the category of endofunctors, which means it combines structure-preserving self-maps. A monad is a monoid in the category of endofunctors.