I don't know what freesync/G-sync is
I'm so sorry.
Sometimes, we assume people know these things.
I'll give you the most basic terms idea of what Freesync/Gsync does.
Also a youtube video explaining it since apparently people prefer to watch videos over quickly reading something =D
https://www.youtube.com/watch?v=5Ey-KObDABI
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This is the last part of this and is basically what Freesync/Gsync does in even more basic terms since I can be very long winded and other posters here even more so:
So, lets say now that you are playing a game, and you enter a particularly demanding area where you get FPS drops. Instead of the gaming looking choppy and poor, it will still look smooth. Basically, it will make 40-50 FPS scenes, feel like 60 FPS scenes.
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So the current monitor you selected. It displays 60 images a second. This just always happens.
Now, separately, your GPU is feeding the monitor images. Each time the GPU has an image ready, it feeds the monitor that image. So if you're getting 40 FPS. It feeds the monitor 40 frames per second.
Your monitor however, it displays 60 images a second, it doesn't matter WHAT that's what happens.
When you enable Vsync, and are able to drive 60 frames per second with your graphics card, then you can sync up the monitor and graphics card at 60 frames per second.
When your GPU is not able to display 60 frames per second, to match the monitor displaying 60 images per second, it will create a tearing effect, and in general create a worse gaming experience.
With Vsync + your GPU driving 60 frames per second to match the monitor, this creates a FAR superior and smoother gaming experience.
What Freesync/Gsync does now is remove the limitation of HAVING to have 60 frames per second. With Gsync/Freesync, the monitor isn't limited to only 60 images per second. It now is able to dynamically shift the amount of images it shows per second to match your GPU.
So, lets say now that you are playing a game, and you enter a particularly demanding area where you get FPS drops. Instead of the gaming looking choppy and poor, it will still look smooth. Basically, it will make 40-50 FPS scenes, feel like 60 FPS scenes.