That's a weird title. Hops very much do not define beer. Beer was brewed for 12,000 years before hops became common.
The terms eventually evolved to mean the same thing, as pretty much all brews became hopped.
The interpretation will vary a lot depending on the culture and the century you are digging into.
Some references: https://zythophile.co.uk/2009/12/14/the-long-battle-between-...