Translation:What is it?
That's interesting, that the short version ("Qu'est-ce?") is more old-fashioned/formal than the long version ("Qu'est-ce que c'est?")! Thanks for letting us know.
I take it "Qu'est-ce que c'est?" is pronounced something like "kess keh seh?" Unless it's used later in the course, perhaps Duolingo should be updated...