G-sync, rundown, V-sync???

Solution
You can read this for more info: http://www.anandtech.com/show/7582/nvidia-gsync-review

The short answer is this:

V-sync forces the GPU to wait for the monitor to be between refreshes before it is allowed to send an image to the display.

G-sync forces the Display to refresh its image when the GPU finishes a new frame.

Since GPU's generate frames at an inconsistent rate, it is a big advantage to have the monitor sync with the GPU's rate of delivery, and not the other way around.
You can read this for more info: http://www.anandtech.com/show/7582/nvidia-gsync-review

The short answer is this:

V-sync forces the GPU to wait for the monitor to be between refreshes before it is allowed to send an image to the display.

G-sync forces the Display to refresh its image when the GPU finishes a new frame.

Since GPU's generate frames at an inconsistent rate, it is a big advantage to have the monitor sync with the GPU's rate of delivery, and not the other way around.
 
Solution