Before we get into the types of liquors you should know a little about how liquor is made and categorized. Liquor is produced by distilling fermented grain, fruit, or vegetables. This excludes beverages like beer and wine, which
are fermented not distilled. Another distinct fact about liquor is that liquors have no added sugar. Liquors with added sugar and/or flavorings are known as liqueurs. A couple liqueurs include Grand Marnier and Frangelico.
The amount of alcohol in liquor is described by alcohol proof. In the US proof is exactly double the alcohol content. Therefore if the liquor bottle is 80 proof, it contains 40% alcohol. The term originated during the 18th
century in Britain when sailors would "proof" their rum rations by dousing gunpowder in them to see if it would ignite. They did this to make sure their rations had not been watered down.