Your Mac desktop screensaver is the most high profile item on your computer, screensaver could also be chosen by the default available screensavers of the system, third-party screensavers or you can create your personalized screensaver by combining the images of your choice.
These are the steps to apply or change a screensaver in Mac system.
Click on Apple logo and System Preferences from menu
In Personal click on Desktop & Screensaver
Click on Screensaver button
Select screen saver of your choice from the right list under Screensavers
Click Options tab to make some settings for screensaver
Make settings of your choice and click OK
Set time for screen saver by dragging the bar right or left on Start screensaver bar
After all settings click on Test for preview of your applied screen saver
In Mac we can also apply Pictures screen saver. Pictures could be selected from the already added pictures or by browsing a picture folder from Mac. The process is as follows
Click Pictures and select any picture of your choice
Click on Options to make different settings and after that click OK
We can add our personal pictures folder to make a screensaver. Click on Choose Folder…. under Pictures
Select images folder of your choice from computer as we selected Pictures folder and click Choose
Pictures folder is added under Pictures and applied as a screen saver. All the settings as Options, Display Style etc… could be applied on this folder as well