So yeah, Tequila is only made from Agave tequilana AKA agave azul AKA blue agave AKA Weber agave and that plant has to be grown and distilled in any of the five Mexican states allowed for tequila production. Map below.
Maybe you see on this map that Jalisco who makes Tequila shares a border with Zacatecas who makes mezcal. Divided by the Boloños river (I didn't label that), these two states may grow the same agave azul, they may live on either side of the river, waving their pointy agave leave at each other for years, they may even be harvested and processed in the same way, but one will be Tequila and the other Mezcal.
The video below better explains the still maps above.