Let's pretend that Windows OS and Mac OS are video game consoles.
The windows console is very easy to put together and it's cheap. It comes with all the cords and controllers that you need. It's very popular and a lot of people have it. Because of it's popularity, all the games you buy for it will work right out of the box. You just put it in the disc tray and play. Every video game is made to work with the windows console. But you can't change the main part inside the windows console. It is made at the windows factory and you can't open the console up. The quality is okay but it does mostly everything you want.
The mac console looks really nice and is fun to play. It is made with it's own special parts and controllers. It doesn't play all the video games, but the video games it does play are very good. It's kind of popular, so a lot of the video game makers will put special mac logos on their discs. You can't change the main part inside as well as a lot of other things. All the mac console accessories work together without any extra work.
Just a reminder that this article is talking about the operating system(OS), not the hardware.
The OS is the software such as or .