Explain Open Source Software Like I'm 5

I don't know if this is supposed to be amusing or informative, but I don't think it does either.

For example...

> Linux is an alternative operating system (the software allowing apps to use a graphic based interface) to Microsoft Windows or Apple MacOS. Linux is the largest open source project in the world.

...involves a parenthesis that is just plain wrong. That's not the job of the operating system. It's a common thing that some operating systems do, but that's just one of the user interfaces available to an OS. Linux, the kernel, is maybe the largest open source project in the world, but that's "just" the kernel. The operating system would be Debian GNU/Linux, or Ubuntu, or whatever, and some manner of X11 might be on top of that to provide something for a GUI to draw windows in, thus providing a GUI, but the OS can run entirely in textmode, or even completely headless. Ask your router, if you don't believe me.

I mean, this is a level of detail I wouldn't lay on a 5-year-old, obviously, but I'm confused as to why this is even brought up when it's so inaccurate. This sort of "uh, yeah, I guess, kinda" is soaking through the whole article, making me think maybe it was intended as a joke? Maybe there is a cultural or language barrier preventing me from "getting" the joke?