The only problem is that they will share the resources, so you'll have to be careful with RAM if you don't want to have problems. The hosted OS can be run at any moment as if it were a common program, without having to restart the computer.
That means that you can run Windows on Mac or Linux. What? Yes, virtualizing an Operating System is to run them on other OS. If you need to install Windows, Linux or any other Operating System in your computer, one of the best choices is to virtualize them.
