Liquor refers to distilled alcoholic beverages like whiskey, gin, rum, vodka, tequila, and brandy. These are almost always more potent than fermented alcoholic beverages like beer and wine.
It's best to store liquor in a cool, dark place, and to drink it within a year after opening the bottle. Unlike wine, liquor stops aging once it's bottled.
Don't confuse liquors with liqueurs, which are made with liquor but sweetened and flavored with herbs, fruit, spices, flowers, nuts, or roots.