What is the difference between pulque, mezcal y tequila? If interested there's a song in French by H.F. Thiefaine called "pulque, mezcal y tequila"?

Pulque, mezcal, and tequila are all Mexican drinks made by the agave plant.
Pulque is the only one of the three that is not distilled, it is only fermented, and has an alcohol content similar to beer.
Mezcal is a distilled spirit made by harvesting the heart of the agave plant (the pina) and roasting it in underground pit ovens. It can be made from dozens of different varieties of agave.
Tequila is a specific type of mezcal made exclusively from the Blue Agave variety, and is often aged in wood barrels.

Nice article about the three: https://www.mexperience.com/the-difference-between-tequila-mezcal-and-pulque/