It's kind of like email in the sense that I can email someone @gmail.com from @hotmail.com. As long as I have an email account on some server somewhere on the Internet I can email anyone else that also has an account on some server somewhere on the Internet, even if the accounts live on different servers.
The fediverse is set up kind of the same way. You can interact with people if you know how to find their account, the address of which is formatted similarly to an email address. You and whoever you're interacting with don't have to have accounts on the same server to communicate with each other.
The fediverse is set up kind of the same way. You can interact with people if you know how to find their account, the address of which is formatted similarly to an email address. You and whoever you're interacting with don't have to have accounts on the same server to communicate with each other.