What is business model in this site?

I mean we know there are many other sites where can learn of course not for free so there have business model. But in this site what is that?

By taking this course, you agree to let us sneak into your home at night and use your kitchen faucet to bottle water, which we then use to feed our crop of specialty carrots that are sold to the world’s economic elite on the promise of super-enhanced night vision. I also like to check people’s couches for loose change while I’m there.

But for reals, it’s a free and open source curriculum that depends on donations and a community of contributors.

Is freeCodeCamp really free?=
Yes. Every aspect of freeCodeCamp is 100% free.