A corn tortilla is a thin, round flatbread made from nixtamalized corn: dried corn simmered and soaked in an alkaline lime-water solution, then ground into a dough called masa. Nixtamalization softens the corn, makes it easier to grind, and increases the availability of niacin and other nutrients.
Corn tortillas differ from flour tortillas, which are made with wheat flour and fat rather than masa and have a more elastic, chewy texture; corn tortillas are sturdier when fried but crack if overworked or allowed to dry out. They form the base for tacos, enchiladas, quesadillas, and tostadas, and are cut and fried into tortilla chips.