Taco is a type of Tex-Mex food that consists of a small, folded or rolled tortilla filled with various ingredients such as beef, chicken, vegetables, and cheese. It is often served with a shell, which can be either hard or soft. The shell is usually made from corn or wheat flour and is filled with the same ingredients as the taco itself. Tacos are a popular dish in Mexico and the United States, and are often served with salsa, guacamole, and sour cream.