I almost typed "ale" instead of beer. It was bottled London Pride. Which is that?
Both are generic terms for the same thing, but from different languages. Ale is Norse, beer is Germanic. London Pride is therefore both beer & ale.
Beer (but not ale) has a legal definition in England & Wales (I'm not sure about Scotland), which specifies a minimum alcohol content. Therefore one can label commercial products as low alcohol (or alcohol-free) lager or ale, but not beer.
In modern English usage (but not for the Scandinavian cognates for 'ale), 'ale' excludes lager (pilsner, whatever you want to call it).
Any other differentiation between the meaning of 'beer' & 'ale' is made up by pretentious twats.