A same password for several names (the account or its characters hosted below - see User Manual), and API keys for some WebApps (it's like extensions or plugin, to use IG or using a browser):

On external chat: login with your character name
On game: login with account
Login to a Webapp using a API key (useful to find mektoubs and apartment places and Inventory)
(french image) Ryzom Installer: the entry point to play, configure and manage profiles
(french image) Contact the Official Support using Forum (the best is to login with character name, and you can test your password, but you can use it, event not logued)
Compte ryzom: connection
Free account example, how to sub