What is a "domain" in the context of AuthPlugin in MediaWiki?

Question

I'm writing my own AuthPlugin for MediaWiki, and refering to the doc and the code provided officially. There're several functions about domain:

AuthPlugin::domainList()
// Get a list of domains (in HTMLForm options format) used.

AuthPlugin::getDomain()
// Get the user's domain.

AuthPlugin::setDomain($domain)
// Set the domain this plugin is supposed to use when authenticating.

However, I don't understand what is a domain, how is it supposed to be? Is it whatever the writer of the AuthPlugin extension wants it to be, rather than having any significance in a default MW configuration?

Answer 1

This is mostly for the LDAP plugin; if your auth system doesn't have a concept of multiple domains that might need to be selected from then you don't need to worry about it.