Vsync synchronizes the framerate with the refresh rate, no matter how fast your GPU can render them. The GPU can typically render the frames much faster than the 60 FPS that the screen allows, so instead of loading a frame that just happened, your screen may be loading a frame that happened 1/60th of a second ago. The advantage is that the screen always receives a full frame so you don’t get any tearing. The downside is that your inputs may appear delayed by a frame or two.