By definition, soup is any combination of vegetables, meat or fish cooked in a liquid.
It may be thin (like consomme), thick (like gumbo) or chunky (like chowder or bouillabaisse), or silky smooth (like bisque).
Most soups are served hot, but some like vichyssoise, gazpacho and fruit soups are cold.
Soups are traditionally served as a first course but can also be a hearty meal in themselves.