How does NFM vs FM work

So I have some UVK6s with IJV firmware and I noticed that in CHIRP the NFM option is gone for "Mode", despite being in the default firmware (and also in UV5R firmware). WFM is still there though.

I'm just trying to figure out why that is. For this firmware, there is another bandwidth field for selecting bandwidth. So what I am asking: is the difference between NFM and FM just a different bandwidth?