In the kingdom of beer, there are two large classes: ales and lagers. The former use top-fermenting yeast and require as little as two weeks to make; the latter, bottom-fermenting yeast and require weeks or months to produce.
Lagers tend to be smoother, with narrowly-defined flavors. Examples: pilsner, dunkel, Helles, schwarzbier.
Ales tend to be fruitier, with flavors that are more vivid and layered. Examples: India pale ale, pale ale, brown ale, barley wine. Craft breweries produce far more ales than lagers, although there are exceptions.