Despite being a simple topic, the monad belongs in the advanced section of the Scala language. It is important to understand that a monad is not a class or a trait; it is a concept. Thus, a monad represents an object that wraps another object in Scala. Each step in Monads has an output that serves as input for subsequent steps. Although Scala's maximum collections are Monads, yet not all Monads are collections. Some Monads, for example, can be used as containers like Options. To put it succinctly, the data types that implement map and flatMap() (such as options, lists) in Scala are called monads.
