Lagering as a process was discovered roughly 200 years ago in Bavaria.

Lagers are made with bottom fermenting yeasts. These yeasts sink to the bottom of the brew during fermentation and activate at low relative  temperatures compared to ales. Fermentation takes much longer than it does with ales at these lower temperatures.

The flavor of a lager can be quite simple, with the most mild being light lagers. The most complexly-flavored lagers are usually the darkest,  although few lagers feature strong hop flavoring compared to an ale of similar alcohol by volume. In general, however, lagers display less fruitiness and spiciness  than ales, simply because the lower fermentation temperatures associated with lager brewing cause the yeast to produce fewer of the esters and phenols associated with those flavors.