A sauce is a liquid that is used to add flavor to food. Sauces can be served by pouring them on top of food, or by having them on the side, like the dipping sauce in the picture. Two of the most popular sauces are soy sauce and tomato sauce, or ketchup. Gravy is a sauce made to accompany meat, and chutney is a thick sauce made from spice and vegetables. Sauces can be any thickness, from really watery to very thick and chunky.