AMD FreeSync (Smart Display for Gaming) is AMD's innovative technology that utilizes industry standards such as DisplayPort™ Adaptive-Sync to achieve dynamic refresh rates. With AMD FreeSync (Smart Display for Gaming) technology, the refresh rate of the monitor is synchronized with the frame rate of the graphics card compatible with FreeSync (Smart Display for Gaming) technology, which greatly reduces input lag and reduces or completely eliminates the problem of playing games and playing video. The phenomenon of stuck, blurry screen and tearing has fundamentally solved the problems of the majority of users. Users can enable AMD FreeSync (Smart Display for Gaming) technology via DisplayPort and HDMI® connections.
What is the difference between FreeSync, FreeSync Premium, FreeSync Premium Pro?
What is the difference between FreeSync, FreeSync Premium, FreeSync Premium Pro?
Refer to AMD official advertising compare pictures:

Additional instructions:
You can refer to AMD's official introduction to FreeSync Click here:https://www.amd.com/en/technologies/free-sync
Not all games support FreeSync Premium Pro