I’d say that both White Castle and McDonalds are a separate food entity. In form, they’re both burgers. That much is true, but the overall thing that you eat is consistently something else.

This is may be more obvious for WC because in spite of being the oldest fast food hamburger, they also depart more radically from the norms of cooking and presentation. Whatever McD’s is doing is a little more arcane. It presents itself as a burger, but doesn’t really taste like a burger.

And if you’re adding regional chains, Culver’s deserves a mention.