Facebook is not just a social media and the biggest website in the world. It is a service which has radically changed our lives. And it did it without our noticing, too.
Take the way we communicate, for example. It is now possible to stay in touch with your relatives and friends and keep absolutely quiet while doing so. Humanity has been using speech for tens of thousands of years. Compared to that, writing is a relatively new invention. Then, Facebook further revolutionized communication by allowing us to talk to each other without using our mouth muscles at all.