I am considering to buy myself a new monitor.
There are two models, first has an AMD FreeSync and second has an AMD Adaptive-Sync support. Both are 75Hz IPS FullHD 21.5" monitors from Acer.
Honestly, I have never heard of "AMD Adaptive-Sync" technology, just heard of AMD FreeSync. I know that "Adaptive-Sync" technology is a part of VESA DisplayPort 1.2a standard, so ... what exactly is "AMD Adaptive-Sync"?
One more question, both monitors have 75Hz max. refresh rate and 56Hz min. refresh rate using FullHD resolution. Should I expect frame tearings in situations where FPS drops below 56 even if AMD FreeSync is enabled?
It's the same thing. As for if you will see frame tearing under the adaptive sync range, then that's going to depend on how sensitive you are to it.
They are the same thing. Freesync was just a slang term when the technology first came out to refer to AMD's Adaptive Sync. The term "freesync" eventually caught on to the point where everyone including AMD themselves started referring to the technology as "AMD Freesync".