Remote Install Mac OS X is a remote installer for use with MacBook Air laptops over the network. It works by having it run on a Macintosh or a Windows-based PC with an optical drive and then connecting over the network to a client MacBook Air (lacking an optical drive) to perform system software installs.
Remote Install Mac OS X was released as part of Mac OS X 10.5.2 on February 12, 2008.
Starting with the March 2009 version, the Mac mini also supports Remote Install, allowing the DVD drive to be replaced with a second hard drive.
A support page is available on Apple's website describing Remote Install: http://support.apple.com/kb/HT2129.
With the launch of OS X Lion, Apple has omitted Remote Install. A workaround is to enable Target Disk Mode.