"Spirits" and "liquor" refer to the same thing: a hard alcohol product made by distillation, typically with an alcohol by volume (ABV) of around 40%. These products are usually unsweetened, though they can be flavored.
It's important to note that the term "spirit" or "liquor" does not encompass all products found in a liquor store, aside from wine and beer. For example, items like Grand Marnier, Amaretto, or Angostura bitters are considered part of the extended spirits family, but they are not pure spirits because they contain added ingredients such as sugar, herbs, and spices, and generally have lower ABVs.
To identify a spirit or liquor, look for specific information on the bottle label. This typically includes the brand name, the type of spirit (e.g., vodka, gin, tequila, rum, whisky, mezcal, pisco, or cachaça), any further required details (such as the age of whiskey if it's under four years), the alcohol by volume (ABV) expressed as a percentage (often also labeled as "Proof"), and the country of origin.
