iCloud: Back to My Mac
Back to My Mac is an iCloud feature that lets you securely transfer files or control a remote Mac via screen sharing over the Internet. Using Back to My Mac you can:
Share files: Browse your remote Mac computer’s hard drive, and drag files and folders to your local Mac.
Screen share: Control your remote Mac just as if you were sitting in front of it. Screen sharing opens a window displaying the desktop of your remote Mac. You can use your mouse and keyboard to open applications, edit documents, and more.
If you turn on Back to My Mac when you set up iCloud, you can see your other Mac computers in the Shared section of the Finder sidebar. Back to My Mac requires the same iCloud account setup and OS X v10.7.5 or later installed on each computer.
For more information, choose Help > Help Center.