This makes sense, thank you. I’m becoming so aware of how little I know about software (I had to look up the term frontend).
Is this right: Mastadon is an open source frontend and ActivityPub is the open source backend. And Mastadon is kind of like a tool that people use to create instances. The instances keep all of their data on their own servers, but the servers can talk to each other so every server has access to data from every other server. So if Musk bought Mastadon, he wouldn’t have control of all the individual servers’ data, and if Musk bought a server, all the users who wanted to could switch to another server without losing any of their data. Does this mean that every server holds a copy of all of the data from the whole network of servers?