Soup is a primarily liquid food, generally served warm or hot (but may be cool or cold), that is made by combining ingredients of meat or vegetables with stock, milk, or water.

Hot soups are additionally characterized by boiling or simmering solid ingredients in liquids in a pot until the flavors are extracted, forming a broth.

The earliest evidence for soup in human culinary practice dates to the Upper Palaeolithic period when thermally altered rocks became commonplace in the archaeological record.

Based on ethnographic evidence, some archaeologists conjecture that early humans employed hides and watertight baskets to boil water.

The word restaurant (meaning "[something] restoring") was first used in France in the 16th century, to refer to a highly concentrated, inexpensive soup, sold by street vendors, that was advertised as an antidote to physical exhaustion.

[8] In the US, the first colonial cookbook was published by William Parks in Williamsburg, Virginia, in 1742, based on Eliza Smith's The Compleat Housewife; or Accomplished Gentlewoman's Companion, and it included several recipes for soups and bisques.

In 1794, Jean Baptiste Gilbert Payplat dis Julien, a refugee from the French Revolution, opened an eating establishment in Boston called "The Restorator", and became known as the "Prince of Soups".

Portable soup was devised in the 18th century by boiling seasoned meat until a thick, resinous syrup was left that could be dried and stored for months at a time.

The soup is usually doubled in volume by adding a "can full" of water or milk, about 10 US fluid ounces (300 ml).

[citation needed] Microwaveable bowls have expanded the "ready-to-eat" canned soup market even more, offering convenience (especially in workplaces), and making for popular lunch items.

Dry soup mixes are sold by many manufacturers, and are reconstituted with hot water; other fresh ingredients may then be added.