There are so many ways to categorize beer: by color, by yeast type, by prominent flavor, or even by popularity of the style. But, much like wine, distinct styles of beer are typically developed by region, and the raw materials most readily available in that region.
"Beer is different. For starters, almost all beer recipes are based on two-row or six-row barley, two types of grain that display similar, though not identical, flavor wherever they are grown. For this reason, beer styles developed regionally for reasons other than the distinction of the base ingredient. These reasons were many: Weather affected a brewer’s ability to lager beer; natural water chemistry and qualities like “hardness” dictated if pale or dark malt could be successfully brewed with; hops grew abundantly and were used in equal measure, or else they were imported and, therefore, used sparingly. Finally, the wild yeast of the region determined if the finished beer would display expressive fermentation character. or the flavors of its base ingredients."
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