A print screen function on a PC is performed by pressing the PRINT SCREEN key on the keyboard. The key may also be labeled PRTSC or PRTSCN on some models of keyboard. Some keyboards may be lacking this button altogether and require a particular keyboard combination, such as FN+INSERT, to perform the function, depending on the model.
The print screen function takes an image of the entire work screen and holds it in memory for uses such as pasting into another application such as email or the Paint application. Alternately, using the key combination ALT+PRINT SCREEN only copies the currently selected window.
The misleading name of the function is because the print screen function was originally designed for command line operating systems such as MS-DOS. In MS-DOS, the print screen function would actually print the current screen buffer to the standard printer port, commonly LPT 1. Users could also press the CTRL button in conjunction with PRINT SCREEN to turn on and off the printer echo feature. Printer echo would cause any output sent to the screen to simultaneously be sent to the printer.
In a modern operating system, the image is instead saved to the system clipboard in a bitmap format that can be pasted into image editing software or directly into word processor applications or email. For Windows 8, pressing WIN+PRINT SCREEN saves the image to disk.