How to change resolution and set the screen saver in Linux?

Please click on the lower left corner icon (also start button), system Settings, open the interface, in which to choose show and monitoring icon, click on it, will popup the specific configuration window:



In the left column to choose the size and direction, can modify resolution, refresh rate, etc.
In the left column to choose screen saver, can choose the black screen and random two modes. And configuration waiting before automatic startup time, etc.
Set up is completed, click on the test to see the effect, if it’s ok, direct application, then close it.