A screen shot (sometimes called a screen capture) is an image of a computer desktop that can be saved as a graphics file. Various programs are available for creating screen shots, but it is easy to do without any special program.
To take a screen shot on a Windows platform , first press the Print Screen button (usually on the top row of the keyboard). The screen shot is copied to the clipboard, the memory area that temporarily stores information. The image then has to be pasted into a document in a word processing program such as Word or into an image editor, such as Adobe Photo Shop. (The mouse cursor is not included in the image.) To get a shot of the active window only, press the Alt key and the Print Screen key at the same time.
On a Macintosh platform, press the Command, Shift, and numeral three keys together to create an image file.
On a Unix platform, there are different methods for the various interfaces. A common one is the command xwd -out filename.xwd, which allows you to click a screen to make an image file.