Screenshot on Mac can be made standard means of the system. No additional applications need to be installed. Now I will tell you how to print screen mac (screenshots) on the example of all macOS version including new macOS Mojave. Ok. Let's go bro.
How To Print Screen on a Mac:
Command (⌘) + Shift (⇧) + 3 - a screenshot of the entire desktop. If you have multiple monitors, the same number of files will appear.
Command (⌘) + Shift (⇧) + 4 - a screenshot of the selected part of the display. The arrow cursor turns into a sight with the current coordinates. You just have to choose the area of interest.
Command (⌘) + Shift (⇧) + 5 - opens the program Screenshot (only on macOS Mojave).
All these combinations can also be used with the Ctrl key. In this case, instead of saving to the desktop, the image will be immediately saved to the clipboard.
If you are going to publish screenshots somewhere in a blog or forum, it is better to optimize their size before posting. So they will load faster.
How to check macos version:
Tab + "About This Mac" = You. can see your macOS Version