A Jewish bagel weighs about three times as much as a non-Jewish bagel, and is about three times as dense. It doesn't have the airy, bread-like consistency that a non-Jewish bagel has. As my Jewish friends like to say (paraphrasing), "If I can throw it at your head and risk knocking you out, then it's a Jewish bagel."
I've never had a bagel that was "airy", but I've also never had one that was made without yeast. They're normally pretty chewy, but definitely not unleavened. You boil and then bake them.
