If Classic Era, then you’re on one of, if not the largest server clusters:
A server cluster means you can join instances, guilds, raids, trade items, share the AH, etc. with everyone else in the same cluster. Effectively the same server, but you don’t have to change your character name, if someone else on one of the connected realms has the same character name.
There were some free transfers for Classic Era, mostly to Whitemane, which as stated above is part of the same cluster that Fairbanks is, and I don’t think it applies to other servers in the same cluster, if it’s still happening.