What is the difference between a ‘Mixto Tequila’ and tequila with additives?

To be classified as “tequila” the product has to be made from 100% blue agave and is permitted to have a maximum of 1% of additives. A “mixto tequila” has at least 51% of its volume made from blue agave distillate and the other 49% can be distilled from other non agave sugars (usually sugar cane).