Illustrate part of a software program or a website. Create an image of a game you are playing online or make a background image which will decorate your Windows desktop. Screen shots can be used to do all of this. It is very easy to take a screen shot and turn it into an image file. Whether you use the Windows operating system or Macintosh or Linux, there are plenty of options.
Getting Your Image Captured in Windows
Press the "Prt Sc" key in the program where you want to capture an image, such as in a web browser when you see something you would like to capture for viewing later on. The trick is to make sure that the image is saved soon after the capture, because the Windows Clipboard overwrites every captured item, whether it is text or an image, with the newly requested item. So this should be remembered for images that arrive on your screen and are replaced with new images that you want to capture very quickly, because you will have to be very quick about saving those images. (Whatever you cannot save immediately after the capture will be lost.)
Options for Screen Capture in Windows
Some software allows for multiple screen capture; but, unless you want to capture a set of moving images, you will probably have no need for this. If you want to capture moving images, you would probably do better with a program that does just that, such as Replay Screencast or Camtasia. Be aware, however, that this would involve making an additional purchase of third-party software.
You do have options for single screen captures, though, by using what is already included in Windows. If you want to capture just the client image in a program and not the whole screen, you can do this by holding down the "ALT" key while you press the "Prt Sc" key. This will only capture the active window (the one with the title bar showing as being active).
Saving Your Work in Windows
With the screen shot captured, save it as soon as possible. If you are getting ready to take screen shots, you would be wise to have a program like MS Paint open so that you can save the image right away. You can save screen shots in the MS Paint program (or any other graphical editor, such as The GIMP, Paint Shop Pro, PhotoShop, Paint Dot Net or InkScape).
With your choice of graphical editor open, use the key combination, "CTRL"+"V" which will paste the image into the program. You can then save it as a file in the format of your choice, limited only by the program's file format limitations.
Taking a Screen Shot in Other Operating Systems
Take a screen shot on a Mac by using different key combinations. Depending on whether you use the "Control" key in combination with the Command key will determine the destination of the screen shot.
Adding the "Control" key to the other combinations will direct everything to the Macintosh Clipboard. If you just press "Command"+"Shift"+"3" or "Command"+"Shift"+"4" you will save it as a file on to your desktop. The key combination using the figure "3" simply creates a snapshot of the screen as a file on the desktop; using "4" allows you to select an area, and if you add the "Space" key afterward and click a window, you can get a screen shot of that specific window.
Note: on a Mac, it also depends on which operating system you are using as to how the screen shot will end up. The "Leopard" operating system adds even more options to the final shape and size of your screen shot. "Jaguar" gives you a JPG file. "Panther" produces a PDF. "Tiger" and everything before that creates a "PNG" file by default (although there are options in the terminal window to change these to whatever you want). Of course, you can also use the Grab applet included in OS X (/Applications/Utilities/Grab) instead of key combinations, and there are also third-party applications.
In Linux, there are some excellent utilities for grabbing screen shots. Probably the best is "Shutter," which has been written with the express purpose of providing all the possibilities for screen capture in one application. However, command-line options include: "scrot" and "eog" (for the GNOME desktop). Some of these permit multiple screen shots and have a facility for combining all of them. "XscreenCapture" is an included utility in most flavors of Linux. The GIMP graphics package also contains an "acquire screen shot" tool.