Screen shots / Screen captures
Both Mac and Windows computers can capture the contents of a program window for use in other programs.
Windows
Start by arranging your screen or program window the way you want it and, in the case of windows, sized to suit your needs.
To capture the current window, hold down the ALT key and press the PrtSc key.
To capture the entire screen instead of the current window, press just PrtScr.
This puts an image of the current window or screen on the clipboard.
Switch to any other application and choose Edit, Paste or press Ctrl+V to paste the image.
If you want to save the image to a file for later use, paste it into MS Photo Edit, MS Paint or any other image editing program and save from there.
There are many commercial screen capture programs that provide much more flexibility and many more ease-of-use features. SnagIT, by Techsmith is one of the favorites among PowerPoint users.
Mac
Mac OS lets you save a picture of the screen directly to the Desktop or lets you put it on the Clipboard using keystrokes. If you choose to save, the first picture is cleverly called "Picture 1" and subsequent captures are sequentially numbered. In OS X, the captures are saved in PDF format, but they can be converted with Preview. In OS 9 and lower, they are saved in PICT format, but again, they can be converted using a converter utility.
To capture the entire screen and save to the Desktop, press the following keys: Apple + Shift + 3.
To capture a portion of a screen press: Apple + Shift + 4, drag a selection box with the mouse, then let go of the mouse to save the screen capture.
To capture the active window in OS 9 or lower, turn on Caps Lock, press Apple + Shift + 4, and click the active window. If you would like to see this functionality in OS X, please send feedback directly to Apple
If you'd rather save the screen shot directly to the Clipboard for pasting into another application, simply hold down the Control Key along with the Apple and Shift keys.
OS X includes a utility called Grab that allows you to take screen captures without using the keystrokes. You can find it in Macintosh HD/Applications/Utilities. The resulting screen shots can only be saved in TIFF format, but these can be converted after they're saved using Preview.
Snapz Pro X is a professional screen capture utility for OS X that provides increased functionality over Grab and the built-in keystrokes. Learn more about this application at the Ambrosia Software web site