It can run Windows 7,Vista, Windows 2000, Win 98, 95, Linux and UNIX operating systems, using the same guest OS concept that emulators do. You install a virtual disk on your Mac containing the guest OS, and it sits in a window. With the push of a button, it can also switch to full-screen mode, looking like a full PC. You can have multiple virtual discs on your system, hard disk space permitting. Parallels exploits a virtualization technology called paravirtualization, which means that a Windows operating system running on your Mac doesn’t have to translate each line of Windows code before execution, but can talk directly to the chip. This saves huge amounts of time. The result is the guest OS runs at near-native speed.
There is no need to reboot here. Also, you can share files between Mac and Windows desktops, and even cut and paste text between them. OU mac users can now quickly swap between Mac and Windows without leaving the comfort of their own desktop. And if that wasn’t good enough, Parallels even allows you to use your Boot Camp partition directly, meaning that you can use the same Windows desktop whether you’re running in Parallels or, if you need full speed, via a reboot in Boot Camp.