Difference between Detail size and Resolution

What is the difference or what change made from 2.78 and 2.79 and how it works in the sculpting under Dyntopo

In 2.78 switching to Dyntopo -> constant detail -> I get option Detail Size

&

In 2.79 switching to Dyntopo -> constant detail -> I get option Resolution

What is the difference and how it work.

Could it be that it’s exactly the same thing, but “resolution” is a better name for it?

I do not think so, they seem to be inversely proportional, currently I can not be precise even if I noticed that to match a small Detail Size of 2.78, on 2.79 I had to set a very large Resolution.