Vodka is a clear, colorless, unaged liquor "made from ethyl alcohol from agricultural origin". It was originally made in Russia from potatoes, but today's vodka, which is almost odorless and tasteless, is usually made from grain, primarily barley and wheat, and occationally from rye.
Someone once said that "A bar without gin is like an Italian kitchen without pasta". No other liquor provides for the creation of so many classic cocktails. Gin is in fact a liquor that is harmonious with almost anything.