After the installation of Windows is complete and you insert your installation flash drive or disc containing the Boot Camp support software (while booted in Windows), it is automatically installed on your Mac.
Depending on your computer’s hardware and OS X version, Boot Camp supports Microsoft Windows Windows XP with Service Pack2, Windows Vista, Windows7, or Windows8
Boot Camp Assistant creates a partition just for Windows without erasing your existing OS X volume.
After installation, you can switch between Windows and OS X by holding the Option (Alt) key at start up