When comparing collections, the idea is, first, to divide collections into sets, maps, and sequences. Collections in different categories are always unequal. For instance, Set(1, 2, 3) is unequal to List(1, 2, 3) even though they contain the same elements. On the other hand, within the same category, collections are equal if and only if they have the same elements (for sequences: the same elements in the same order). For example, List(1, 2, 3) == Vector(1, 2, 3), and HashSet(1, 2) == TreeSet(2, 1).
Read more: Collections equality in Scala