Mac OS X How to take a screenshot
You can press ⇧⌘3 (SHIFT+CMD+3).
to save just an area of the screen, press SHIFT+CMD+4. your cursor will change to a cross-hair allowing you to select an area of the screen. left-click and drag to select the area. when you release the mouse button, the area selected will be saved to the desktop in the format “Screen Shot YYYY-MM-DD at HH.MM.SS AM.png“