Hello. I still don't know the meaning of this concept, and at this point I'm almost too afraid to ask.

What is Federation in terms of this Lemmy instance (chapo.chat)?

I have seen people really excited about this idea, and it came up a number of times when Our Platform was still in development / nascent. I have just seen the concept brought up again in a post in the context of expanding the userbase to include those who may take issue with certain positions within ML/MLM ideology. What is the fediverse? Is it a decentralized "reddit clone" that would shift chapo.chat from being one site to a "subreddit" of independent yet similar forums, functionally? How would instances interact with one another to let users move between them? What do? How work?

Thank you for your time