I'm always looking for ways to improve the smoothness of my games. When I read around the net I come across the term "vsynched" quite often. What does vsynched mean?
It just means that the game matches the refresh rate of the monitor/screen. So if you have a 60Hz monitor (meaning the monitor image is refreshed 60 times a second), the game won't perform above 60 FPS.
If you have vertical synchronisation (vsync) turned off, then if the GPU and monitor go out of sync, then you get an artifact commonly known as "tearing" like so: