Nothing is - together withscala.Null - at the bottom of Scala's type hierarchy.

Nothing is a subtype of every other type (includingscala.Null); there existno instances of this type. Although typeNothing is uninhabited, it is nevertheless useful in several ways. For instance, the Scala library defines a valuescala.collection.immutable.Nil of typeList[Nothing]. Because lists are covariant in Scala, this makesscala.collection.immutable.Nil an instance ofList[T], for any element of typeT.

Another usage for Nothing is the return type for methods which never return normally. One example is method error inscala.sys, which always throws an exception.