screen-sharing-mac-os-xMac OS X 10.5 and greater lets you share your Mac’s screen remotely without requiring any extra software.

To view a different Mac’s screen, open System Preferences on the Mac you want to control and click on Sharing under the Internet & Network heading. Make sure that “Screen Sharing” is enabled. Then open a new Finder window on your Mac and select the remote computer from the Shared list on the left side of that Finder window, click the Share Screen button, and then enter a user name and password for the Mac you are connecting to. That’s it!