Fediverse

The fediverse is an ensemble of federated (i.e. interconnected) servers that are used for web publishing (i.e. social networking, microblogging, blogging, or websites) and file hosting, but which, while independently hosted, can communicate with each other. On different servers (technically instances), users can create so-called identities. These identities are able to communicate over the boundaries of the instances because the software running on the servers supports one or more communication protocols that follow an open standard. As an identity on the fediverse, users are able to post text and other media, or to follow posts by other identities. In some cases, users can show or share data (video, audio, text, and other files) publicly or to a selected group of identities, and allow other identities to edit other users' data (such as a calendar or an address book). Fediverse

Group of social networking sites using the same federation protocol