Depends on the operating system.
In Windows 10 you can do “Windows Key+PrintScreen” which will save a screenshot into your “Photos\Screenshots” folder. Or you can do “Win+Shift+S” to open the snipping too to either select a portion of your screen you want or use one of the various other options Snip & Sketch has. Those are put into the clipboard to be edited in the Snip & Sketch utility. A notification will come up after you take the snip, if clicked, it opens up the editor.
To take a screenshot in macOS it’s “shift+command+3” for a whole screenshot or “shift+command+4” to capture a portion of the screen. If you do “shift+command+4+Space bar,” that allows you to take a capture of a window or menu. All screenshots are saved to the Desktop called “Screen Shot [date] at [time].png”
In a Linux distribution, it may vary between different distros but generally most support the following:
“PrintScreen” will save a screenshot of the entire screen to the “Pictures” folder. “Shift+PrintScreen” will let you pick a specific area to screenshot and save it to Pictures. “Alt+PrintScreen” saves the current window to Pictures. Adding the Control key to any of the above combinations will put the screenshot into the clipboard rather than saving it.