Of all spirits, vodka is—if you'll pardon the pun—the clear winner when it comes to versatility. Deceptive in its apparent simplicity, vodka is a clear, neutral-flavored spirit that is deigned to be relatively tasteless and ordorless.
However, vodkas do have subtleties to them that can often be difficult to describe. Those subtleties—soft notes of citrus, perhaps, or a minerality for example—can come from a number of different sources: what it was made from, how it was distilled, how many times it was distilled, and how it was filtered. Not all vodkas are made from potatos—in fact, most vodkas on the market are distilled from grains, and vodka can be made from anything that is fermentable. The big defining moment comes during distillation, since a spirit can only be called a vodka if it comes off of a still at a minimum of 190 proof. That equates to 95% alcohol by volume (or ABV), and straight vodkas must be bottled at no less than 80 proof (40% ABV). In this section, you can find vodkas made from potatos, corn, wheat, rye, and even from graps and sugar beets. If it can be fermented, it can be turned into vodka with enough encouragment.
Before you start thinking that all vodkas are the same, keep in mind that each has its own character and can offer different dimensions to different cocktails. Take these for example: Grey Goose (made from French winter wheat and filtered through Champagne limestone) and Reyka (an Icelandic vodka made from wheat and barley and filtered through volcanic rock). While both have some strong similarites in their production, they are made with different types of stills (column stills for Grey Goose and the rare Carter-Head still for Reyka), slightly different grains, and different rock filtrations to produce two different vodkas with their own distinct characteristics. Vodkas are a great option for both an all-purpose base liquor in cocktails as well as a playground for discerning palates to try out the endless variety of subtle differences to find the perfect match for your unique tastes.