Jinnan or Jawan (singular Jann) are shape-shifters who lives in the desert, and take the forms of whirlwinds and white camels. They are open-minded about humans, and were among the first jinn encountered by people. They have the power to hide or reveal oases in the desert, depending on whether they like or dislike a party of travelers.
Jann al-Tarnushi was the primogenitor of the jinn who was created by God from simmum or hot scorching desert wind from the earth, in some accounts.
Also in classic texts, the word Jann is just singular of 'Jinn'.