Python type hints: typing.Mapping vs. typing.Dict

Managed to answer this myself.

typing.Dict should be used to indicate a literal dict type with support for element type hinting i.e. Dict[bytes, str]

typing.Mapping is an object which defines the __getitem__,__len__,__iter__ magic methods

typing.MutableMapping is an object which defines same as Mapping but with __setitem__,__delitem__ magic methods as well.

typing.Mapping et al. are based on the abc types in this table