Parallels Desktop for the Apple Mac is for thos who want to use another operating system on a casual basis. It's benefit of fast access to the guest OS is balanced by reduced performance and limited hardware support. It's not a tool to use if you're a gamer, say, but rather for dipping into that legacy accounting or bible software package you're still using after all these years.
That's not to diminish Parallels Desktop. Getting multiple operating system to operate alongside each other simultaneously is an impressive technological feat.
Parallels' software is both very clever and amazingly cheap. Parallels Desktop manages the trick of mediating between guest operating systems, Mac OS X and the hardware they're all running on. The host OS believes its operating alone; the guests each assume they're the only show in town; Parallels Desktop is the cunjuror making it all work seamlessly.
Installation is very simple. Parallesl Desktop itself is installed in the normal Mac OS X manner. Running the installer invites you to set up a Virtual Machine on which any variety of Windows, of Linux or of a number of other operating systems will be "tricked" into thinking they own.
There's no need to re-partitionining. Parallels Desktop automatically creates .hdd files and links them into each VM as if they were physical, separate hard disks.
