Bootcamp
Apple Bootcamp allows you to install Windows on your Mac. With Bootcamp you install Windows onto a new partition of your hard drive. To switch between Mac OS X and Windows you need to reboot your system
Unlike Parallels desktop, Bootcamp only allows you to run either Max OS X or Windows. Not both at the same time.
Note: Bootcamp is no longer a free download from Apple. It’s only available as part of the new Mac Leopard OS.
To install Bootcamp you’ll need to download Leopard.