Burritos and tacos are both elements in Mexican cuisine which involve fillings rolled up in a flatbread wrapper, but there are a few key differences which distinguish these dishes from each other. The most fundamental difference is that burritos are typically much larger than tacos, with a single burrito comprising a whole meal, while several tacos might be necessary for a diner to feel full.
Tacos are an ancient food. The history of Mesoamerican cuisine has included some form of the taco for centuries. Traditional tacos are made with warmed corn tortillas around the size of a hand, folded or wrapped around a simple filling, and sometimes garnished with salsa, sour cream, or other sauces. Most tacos have a single element in their filling, such as carne asada or pulled pork. Some cooks also made tacos in hard shells, which were historically made with stale tortillas.
The burrito, on the other hand, is a relatively recent invention. The development of the burrito is usually credited to an enterprising 20th century merchant who wanted to sell plates of rice and beans without having to provide plates. He stumbled upon the idea of wrapping ingredients in an oversized wrapper made from a wheat tortilla, with the wrapper standing in as the plate and insulating the ingredients. Reflecting these origins, burritos are usually tightly wrapped to form a parcel, rather than simply folded or rolled, as with tacos.
The burrito also tends to have a mix of ingredients, such as rice, beans, and cheese or rice, meat, and vegetables. The tortillas used to wrap burritos are significantly larger than those used to package tacos, being closer to the size of a face, rather than the palm of someone's hand. Corn tortillas are rarely used for burritos, because they can crack and split when made so large, and burritos are sometimes made with flavored tortillas, like spinach or tomato tortillas.
Burritos and tacos in Mexico tend to be quite simple, with basic, fresh ingredients and a relatively small size. Outside of Mexico, these dishes have diverged considerably from their origins. Tacos, for example, may be made with wheat tortillas in addition to the traditional corn tortilla, and the tortillas may also be fried for extra flavor and a crispy texture. The burrito has also ballooned considerably, to the point where some people might not even recognize it, with many Mexican-inspired restaurants outside of Mexico offering burritos stuffed with a multitude of fillings and drenched in sauces.