You can select desirable resolution from droplist, it will consist only supported resolution by your monitor (and videocard).
Refresh rate of the screen. Attention: if you have CRT monitor (catode ray tube)  we urgently recommend to set values according to the manual of the monitor. If you have a LCD (liquid crystal display) monitor it is recommended to leave 60 fps.
Brightness allows increase or reduce brightness of game.
Turning on Vertical synchronization will eliminate a page tearing effect. But on low-end systems can be cause of falling performance.
Game running in full screen mode works much faster than in the window.
Shader terrain mode allows game to look more attractive. Switching-off this option allows to play in game on weak computers.