Salads are dishes without a fixed structure. You can randomly rearrange the ingredients without changing it into another dish. For example, a pizza is salad on top of dough, a burger is salad between buns, and a burrito is salad wrapped in a tortilla. But as a whole, pizzas, burgers, and burritos each have a strict, defined structure, so they aren't salads, they just contain a salad component. Additionally, anything made mostly of liquid by volume is a soup or beverage, not a salad.