There are two types of beer: ales and lagers. Ales are any type of beer that is brewed at higher temperatures (60-75°F). It's the higher temp that allows the specific type of yeast to ferment and quicker than lager yeast. Lagers are brewed at lower temps (around 34°F) and then further stored in cooler temperatures to mature. Lager is a German word meaning "to store". Aside from obvious labeling, a lager will almost always announce itself with lighter, more crisp flavors. Almost always hay/straw in color. Pilsners, marzens and bocks are all prime examples of a lager. There's really not much more to lagers so that leaves just about everything else as an ale. Only a few random styles make an appearance in a 'hybrid' category.