Tostada usually refers to a flat or bowl-shaped (like a bread bowl) tortilla that is deep fried or toasted. It may also refer to any dish using a tostada as a base. Corn tortillas are usually used for tostadas, although tostadas made of wheat flour may occasionally be found. The difference between a tostada and a chalupa is the shape of the corn tortilla. Because the word “chalupa” means “boat” in Spanish, there’s a slight curve to a chalupa that can make it looks pretty similar to a taco. A tostada is also fried but is laid flat to better hold all of its toppings.