Adelphos is Federated
Adelphos is a distributed system; this means that there is not a single instance, a centralized organization that governs it, like facebook, x, ebay or other monolithic systems.
You are probably reading this documentation in the site www.adelphos.it, but this is only the first instance of Adelphos; everyone with sufficient skills in system deployment can deploy a private adelphos instance in a matter of hours and be online with a modest monthly cost (adelphos can run on a laptop without any problem, so electricity bills should not be a problem, we are not talking about costly GPUs for graphics or mining or learning AI).
Communication between instances
Adelphos can be run standalone, in which case all the activity will be done on one site; but the site owner can allow his instance to speak to other instances in order to share users, goods and services.
The way in which the adelphos instances speak together is using the Activity Pub protocol; in this way adelphos is another application in the Fediverse (the set of all the applications the speak the Activity Pub protocol)
Adelphos and Activity Pub
Adelphos, though, uses the AP protocol in a peculiar way, mostly as a secure way to exchange messages between instances and users.
Each Adelphos instances runs a Fediverse account named @adelphos@host (in AP the initial @ is used as a way to distinguish it from a normal mail address). This adelphos account is responsible to
* Send messages to other adelphos accounts (daemons) in order to
synchronize data and tasks
* Send messages to normal human users to notify them of activity in
their account