The only difference between soup and soup:
"Soup" is mainly water as a heat transfer medium, the cooking ingredients are processed and cooked into a more juicy soup. For example: rice soup, ginseng soup, chicken soup, vegetable soup, clear soup.
"Soup" refers to the five flavors of the soup, but also refers to the food cooked into a thick juice. For example: soup, meat soup, egg soup.
Chinese food is usually "a few dishes and a soup", Western food before the meal must have "appetizer soup", from ancient times to the present, the status of soup has never changed. As early as in ancient China, soup and health, medicinal diet closely linked together. We once ignored, once on the soup do not think, and modern people and gradually restore the good habits of every meal must drink soup.
The ancients called soup "soup" and boiled water "soup". For example, China's famous Beijing duck production, still roasted before the duck belly filled with boiled water in the process known as the soup, which is left since ancient times.
Expanded:
The Northern Song poet Lu You has a poem: "tender soup tea milky white (just boiled tea is milky white foam)", which "tender soup" refers to just boiled water. Modern people are accustomed to the thinner called soup, thicker called soup, generally referred to as soup soup or soup soup.
Boiling is the main method of making soup. Soup because of the rich nutrition, fine and rigorous selection of materials, thick and light flavor and is loved by the people.
References:
Baidu Wikipedia-Soup (Food) Classification)