Monad is (a classes of type of) a collapsible container. Collapsible, like how you can flatten a nested list, or Option<Option<A>> can be flattened to Option<A>.
A common pattern with monads is the flatMap function, where you apply function A -> List<B> to (each element of) List<A> to obtain List<B>. This happen to represent erroneous call chaining with Option or Result types.
Monad is (a classes of type of) a collapsible container. Collapsible, like how you can flatten a nested list, or Option<Option<A>> can be flattened to Option<A>.
A common pattern with monads is the flatMap function, where you apply function A -> List<B> to (each element of) List<A> to obtain List<B>. This happen to represent erroneous call chaining with Option or Result types.