The main ingredient in a Mexican taco is typically "tortilla," which serves as the base or shell of the taco. Tortillas can be made from corn or wheat flour and are often soft, but they can also be fried to create a crispy shell. Tacos are highly versatile and can be filled with various ingredients, including meats like beef, chicken, or pork, vegetables, cheese, and toppings such as salsa, guacamole, and sour cream. The combination of flavors and textures makes tacos a beloved dish in Mexican cuisine and around the world.