Stews are typically cooked at a relatively low temperature (simmered, not boiled), allowing flavors. In cooking, a sauce is liquid, cream, or semi-solid food served on or used in preparing other foods. Sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to another dish.

Both soup and stew are a combination of vegetables, meat, or fish cooked in liquid. The main difference between these two dishes is the amount of liquid that's used for each, with stews generally containing less liquid than soup.

Gravy and stew are both tomatoe base source. The diff is stew is more thicker whiles gravy is lighten with either meat or poultry stock with flour thickneing. Gravy is pourable stew is more solid.

Stew is a process, like braising. It's a way of cooking, not a particular food. You can stew meat or vegetables, or both in any combination you like. Sauce is a liquid used to dress a dish.

Soup is a liquid thing you eat on its own. Sauce is a liquid thing you add to other things. Usually solids. Sauces are generally thicker than soups.

Sauces usually come from pan drippings, typically meat fat with added stock. Cooks also thicken them using cornstarch or flour. On the other hand, stock comes from simmering raw ingredients (e.g. vegetables and meat bones). The stock then becomes the bases for soups and sauces.

In soup, the liquid is the primary ingredient. Soup can be completely liquified or it can consist of other elements (like meat and vegetables) that are fully submerged in water, stock, or broth. Stew, meanwhile, is typically "chunkier." It contains just enough liquid to cover the main ingredients.