Like all good intoxicants, people have been drinking it for, like, ever!
Tequila, or its fermented agave great-great-great grandfather "octli" or "pulque," at least, was drank during the Aztecs' reign. Since then, tequila's undergone a number of developments in the manner of production, the style and taste, and popularity. First, let it be known, tequila is NOT mezcal. Only blue agave can be used for tequila (whereas other agaves are used for mezcales). But other than that, there are a couple ways to categorize tequila.
The fundamental varieties of tequila are the 100% pure blue agave tequilas, and the mixtos.
100% of the sugars used to make pure agave tequila is from the blue agave (agave tequilana). Mixtos still contain at least 51%, but the other 49% can be obtained from other sources, like, sugarcane or unicorn horns.
Now, there are a couple more specification to be made...
Traditionally, there are four categories of tequila (outside of the basic two): Blanco, joven, reposado, and añejo. A fifth category, "Extra Añejo," was added in 2006.
1. Blanco or Plata
Well, respectively, "blanco" and "plata" translate to "white" and "silver," but in tequila terms, they mean the same thing. In English, using "silver" is more common. Silver tequilas are either bottled directly after distillation or aged for fewer than two months in steel or neutral barrels. Taste-wise, these are unencumbered by things like maturity and oaky barrels.These are great for mixers as a lot of them are more neutral in taste, other than the y'know, blue agave characteristics.
You can do THIS with it!
Meaning "rested," reposados are aged for at least two months, but fewer than a year. They're usually a light straw color. They have the sweet floral notes like the silver, but have a bit more complexity from the aging. The barrels used for the aging are usually oak, and some have previously been used to age other spirits, like whiskey.
These are great for...
3. Joven or Oro
These are the standard tequilas. They have a solid tequila taste, but not quite the sipping variety, yet. Gold tequilas are usually mixtos. Moreover, these golden nectars are generally a mix of silver tequilas and reposados. With a pronounced enough flavor to not be lost but not as to be overwhelming in a concoction, these are good for just about anything. This is the classic used for margaritas.
Age tequila in an oak barrel for a at least a year and it becomes añejo, which just means...well, "aged" --do it for more than three and it gets the "extra" added to it. These are the tequilas for strong flavored drinks or sipping. Things can get expensive here, but it can definitely be worth it. Sweet, complex, and flavorful, these aren't necessarily the best for benders.