A tortilla is a Latin American flatbread, a pancake-like disc made from masa harina or wheat flour and baked on a griddle.
Though the bread itself predates the arrival of Europeans in the Americas, the name of the bread came from the Spanish, because it resembled an Iberian omelet (traditionally made with potatoes or salt cod) called a "tortilla" (which you can still find at most any tapas bar).
Tortillas can be eaten on their own, or used as an envelope for burritos, tacos, quesadillas or enchiladas. They can be cut up and fried or baked to make tortilla chips. Stale tortillas can be toasted or deep-fried whole to make a tostada shell for salad.