The way it works is that there’s not one lemmy site, there’s many different sites, or “instances” that people can host on their own servers—lemmy.world and lemm.ee are two of these. The catch is that they are “federated”, meaning that a user in one instance can see, vote on, comment on, etc posts from another instance. That’s why you can be on lemmy.world and see posts from !memes@lemme.ml. So if lemmy.world goes down it’s as simply as typing in another instance to your address bar :^)

It's more like email than a regular platform. Each insurance is a Lemmy "provider" but from any instance you can reach every other instance. It even used the @server for user names and communities like email. It also means you have a technology@lemmy.world, technology@lemmy.ml, ...

think of all of this like email, you get data from other providers and interact with people and posts using an "email address". im oversimplifying it, but that's how i started to wrap my head around all of this