Mezcal is the overall term for distilled agave spirits. As such, there are many types of mezcales, made in different regions in Mexico, using various cultivars or even different species of agave. Tequila is a specific type of mezcal made from blue agave. It also has denomination of origin, so additionally for it to be legally called tequila, it must be made in the state of Jalisco or the bordering municipalities (counties) of Michoacan, Guanajuato, and Tamaulipas.

In practice, people separate tequila from the rest of mezcales, much like people set apart champagne from "wine", despite how champagne is literally a specific type of sparkling wine, made in the French region of Champagne.