``cdh`` with no arguments presents a list of :ref:`recently visited directories <directory-history>`. You can then select one of the entries by letter or number. You can also press :kbd:`Tab` to use the completion pager to select an item from the list. If you give it a single argument it is equivalent to ``cd directory``.
Note that the ``cd`` command limits directory history to the 25 most recently visited directories. The history is stored in the ``$dirprev`` and ``$dirnext`` variables which this command manipulates. If you make those universal variables your ``cd`` history is shared among all fish instances.