16 bit vs 32bit float vs 64 bit float

Hi all,
can someone please explain to me the difference in mixing between the above, as I can’t really hear a difference in quality apart from taking up 3 times the amount in HDD space.
I realise that if pushing the master into the red the 32 and 64 bit would stop it clipping but since the introduction of online volume correction, there is no point in doing this any more to achieve ear-shattering volumes. If 32 bit does that, why 64 bit?

I would also like to know the difference between 32 bit and 32 bit float etc…All a bit confusing for me and can’t seen to find much online.

Anyone fancy breaking it down into baby food for me would be greatly appreciated.
Thanks in advance