Screen tearing happens when your GPU’s framerate is out of sync with the monitor’s refresh rate. “Out of sync”, not “more” or “less”. Screen tearing remains to be the #1 gaming issue related to the monitor. But in fact, it’s got more to do with the GPU’s relation to the monitor than just the monitor.
VSync stands for vertical sync. It’s a graphics technology used in games to improve performance in some cases. In other cases, however, VSync can instead be detrimental to your FPS.