Servers, are the multiplayer games that a client, or player, connects to. The Servers are broken up into three components, SQL Database, for login data, character data, world data etc, Login Server and World Server.
Clients, or players, can connect to various servers, or games, the client remembers characters on servers, data is updated upon login into the server in question allowing for an image of the character. The client loads the mods and games, that are sent to the client via list, from predefined folders (in a similar way to Mod Organiser's Profiles, ie not moving the files simply loading them). If the folder doesn't have the game and mods on them it states "Cannot Join" then lists the game and mods needed including the version of them and the location where it can be downloaded.
Characters are played on the server via the client, and updated when you login to the server in question. When selecting Create A Character on the Client you can select from a dropdown, or input a url or ip if the server is not listed. Upon entering this the game loads into the games character creation. Also when creating a character you can toggle Solo play and load a custom profile or server profile.
As stated this is just a random thought that came to me as I was falling asleep last night, and had to write it down. xD