How servers relate to each other

From the point of view of intended use, the servers are either personal servers or shared servers:

Personal Server ... Shared Server ...
Runs on an individual user’s machine Where individual users store their changes so that other users have access to these changes
Used by a single user Used by multiple users concurrently

Client 1 interacts with the Server 1 personal server, which in turn interacts with the shared server.

Client 2 interacts with the Server 2 personal server, which in turn interacts with the shared server.

From the point of the view of Client 1, Server 1 is a local server and Server 2 is a remote server: