seamless integration of windows into mac os. you can open files in windows with macOS programs seamless per double click and vice versa. If you dont want to, you won't see the windows interface again after installation, just your programs whats very useful for working productively. You can move Windows OS - windows over macOS windows and vice versa seamless and won't experience any lags or other. Also the windows system is faster than my old windows laptop. Windows will boot in a few seconds in the background automatically after starting -any- program or file which is associated to an windows program.As an mechanic and software engineer i have to say that i'm more than impressed of this Software (Parallels Desktop). It's rarely that i'm improved by user friendly design.