It's amd's side of Nvidia's gsync, but with a different way of working.
Both do about the same thing : match the monitor hz to the fps, in a range of minimum and maximum hz.
So if your game is doing 103fps and monitor can do 40-144hz. The monitor will match 103hz.
It reduces tearing and can maybe reduce the perception of lag. It doesn't remove it. If you have frame drops you will still see them.
For the ur way of working :
-Gsync uses a physical chip in the monitor to do what it has to do. In addition of beeing a paid technology, it adds to the cost, and nvidia also does a quality control check on the monitors, which also increases costs. Gsync can only be used with nvidia gpus.
- Freesync on the other hand is free (no royalties). Not sure if amd does a quality control or spec control, but they introduced some years ago freesync ranks. Where to get a higher rank of freesync the monitor has to larch or do better than some specs (https://community.amd.com/t5/gaming/introducing-amd-freesync-premium-and-amd-freesync-premium-pro/ba-p/414261). It can be used on nvidia (still called gsync in the driver) or amd gpus.
There are some limitations with these tho, they can only be used with display port 1.4+(or 1.2+, i don't remember) or hdmi 2.1+ because of variable refresh rate support. Except for amd gpus and freesync. Amd gpus support freesync with older hdmi versions.
Hmm, from the average and some reviews here and there, it's sad the game is just mixed.
It's the first to get out with fsr 3 frame gen working mostly well. Fsr upscalling working mostly well, which is very unexpected due to a lot of foliage.
Tho the ui protection to frame gen was implemented in a very shitty way (just a box without frame gen arrount it...).