About Matrix Matrix is an open protocol for decentralised, secure communications.
Matrix Manifesto We believe:
People should have full control over their own communication. People should not be locked into centralised communication silos, but instead be free to pick who they choose to host their communication without limiting who they can reach. The ability to converse securely and privately is a basic human right. Communication should be available to everyone as a free and open, unencumbered, standard and global network.
What app is that? It’s matrix?
Matrix is the protocol.
Synapse is the server software.
Element (among others) is the client software.
Bridges (WhatsApp, Signal, Google Chat, etc) are extra servers that run next to the main server. Generally text only. Any Matrix client should be able to make use of a bridge. Bridges appear as “bots” in your Matrix contact list. Contacts from other services appear as “$name ($service)” and work as you would expect of a chat.
You should know that Bridging breaks end-to-end encryption as the Bridge has the decryption key and Bridges work by “impersonating” you on the other chat service. Don’t use a Bridge you don’t trust. Beeper is a paid/commercial hosted Matrix service with pre-configured bridges for you, including iMessage (which Apple makes painfully difficult to bridge because Apple).