How to Print Screen to the Clipboard on a Mac
This is the typical Print Screen feature in the Windows world. If you want to do the equivalent of Print Screen to the clipboard so that you can paste it into another app, these are the commands to use:
Command+Control+Shift+3: take a screenshot of the entire screen (or all screens if using multiple monitors), and saves it to the clipboard for pasting elsewhere
Command+Control+Shift+4, then select (highlight) an area: takes a screenshot of selection and saves it to the clipboard for pasting elsewhere
If you don't have your sound on mute then you will hear the sound (similar to a shutter click) telling you the image was captured.