The sole function of this key is to take a snapshot or picture of your computer screen and copy it to the clipboard (the clipboard is an invisible holding area for content that is copied).
Use the Print Screen key to obtain Screen Capturesuse the Print Screen key to obtain Screen Captures.
Using your keyboard, press Ctrl + V which will Paste the screenshot in your open document. Now you can Save (Ctrl + S) the document to wherever you wish, make sure to name it appropriately so you can easily find it.
Windows Alt Prt Scr
Another little feature of the Windows Print Screen Key. Pressing these keys...
Alt + Print Screen
...will take a screenshot of the currently selected window, not the entire screen like the normal screenshot function. This allows you to target that specific window that you have open and nothing else. No more cropping those screenshots to grab the content you were after