They're called servers because we wanted to pick words that were familiar to what we were originally competing against, which was team-speak/ventrilo/mumble ser

They're called servers because we wanted to pick words that were familiar to what we were originally competing against, which was team-speak/ventrilo/mumble servers. Picking words people are familiar with in order to convey a concept is a generally smart thing to do. A discord server was meant to be analogous to a ventrilo server. Calling them servers made that idea clear to our users, which helped users understand our product and what purpose a server served. I would say that the term has served its purpose well. Internally we call them guilds, because having a "server server" is a bit ridiculous.