well, no!

Debian is the underlying OS. It doesn't need to have mouse pointers and windows, Debian (and all other Linux) is just a terminal, like the old MS-DOS, if you remember that, literally a black screen with a terminal prompt in the top left corner (scary!)

Debian lets you choose a different DE, they support about 4-5 different ones. Cinammon is a DE. xfce is my own personal fave DE, but it's down to personal choice.