The term “lager”, like many brewing terms, comes from our German Brewing Brethren. It means “storeroom” or “warehouse”. They key reason behind the term is that lager, unlike ale, has a longer fermentation time which leads to a “cleaner” tasting beer than ales. This a basic primer on making lager beers.
Every few years there seems to be some radical underpinning of the brewing word that comes under assault. Remember olive oil instead of oxygen? Saisons fermented above 80F? Dark candi syrup the key to dark Belgian beers? Dry hopping during fermentation? After the debate calms down sometimes brewer’s shift their process en masse, and sometimes most of them say it isn’t worth the expense/effort/trade-off.