Vodka is one of the world's most popular distilled beverages. It is a clear liquid containing water, ethanol purified by distillation from a fermented substance such as potatoes, grain or molasses, and an insignificant amount of other substances: impurities and possibly flavorings. Except for various types of flavorings, vodka is a colorless liquid.

Vodka usually has an alcohol content of 35% to 50% by volume. The classic Russian, Lithuanian and Polish vodka is 40% (USA 80 proof). This can be attributed to the Russian standards for vodka production introduced in 1894 by Alexander III from research undertaken by the Russian chemist Dmitri Mendeleev. According to the Vodka Museum in Moscow, Mendeleev found the perfect percentage to be 38. However, since spirits in his time were taxed on their strength, the percentage was rounded up to 40 to simplify the tax computation. At strengths less than this, vodka drunk neat (not mixed with other liquids) can taste "watery": above this strength, the taste of vodka can have more "burn". Some governments set a minimum alcohol content for a spirit to be called "vodka". For example, the European Union sets a minimum of 37.5% alcohol by volume.

Although vodka is traditionally drunk neat in Eastern European and Nordic countries of the "Vodka Belt", its popularity elsewhere owes much to its usefulness in cocktails and other mixed drinks, such as the Bloody Mary, the Screwdriver, the vodka tonic, and the vodka.

The process of distillation was kept secret for a long time. The first description of a distilling apparatus comes from the 13th century. The device was later described by a university professor in his treatise about wine. To produce beverages containing 60% alcohol with the device, the distillation process had to be repeated several times. The general knowledge about distillation was being slowly developed until 1800, when Edward Adam invented the process of rectification which removed its "bad taste". Further changes were made in 1817 by Johannes Pistorius, a German brewer, who built the first machine that could produce a beverage containing 85% alcohol in just one distillation. In Ireland in 1830 an apparatus was designed that could work continuously and allowed for production of beverage containing almost 90% alcohol. A similar rectification machine, but working periodically, was for the first time used in 1852 in a brewery in Saint Denis by Pierre Savalle. The present-day distillation-rectification machines, designed in the 19th and 20th centuries, are essentially modernized versions of those devices. Currently, such machines can work continuously and produce beverages containing 95.6% alcohol without any contaminating tastes or smells.

The process of distillation with still was widely promoted throughout Europe by Dutch traders. In the 17th century they also played a great role in exchanging the various types of alcohols such as mead, wine, beer, and also the stronger ones such as rum, cognac, whisky and vodka, between the countries of their origin.