After Apple began selling Macintosh systems based on Intel processors, a program called “Parallels Desktop” was released that let you run Windows in a window on a Mac. It instantly became the de facto standard for breaking down walls between operating systems on the Mac OS. Parallels uses a technique called “virtualization,” which creates a virtual computer running within the physical, real computer. Called a “virtual machine,” it can use different operating systems, allowing Mac users to simultaneously run, say, Windows or Linux.
