They&#x27;re streams on map views, a stream on Map itself doesn&#x27;t really make sense because there are multiple ways to interpret a map as a sequence and it&#x27;s not clear what should be the default (e.g. Python defaults to the equivalent of keySet().stream(), but Rust defaults to entrySet().stream()).<p>keySet() and entrySet() return Set-conforming objects because they can, values() can&#x27;t and only returns a Collection, but these three objects delegate much of their logic to the map itself.