One time my foreigner friend asked me about soup when we were eating soup in a Chinese restaurant. We were eating a "West Lake Beef Soup" 西湖牛肉羹.
He asked me whether we drink soup at home every day.
"Yes we do, but not this type." I said.
"Which type?" He asked.
Then I explained basically we have two types of soup: 湯 & 羹
湯 (Tong in Cantonese) is the kind of soup which is cooked from 20 minutes to hours. It is the "liquid" kind such as winter melon soup, peanuts & chicken feet soup etc. People believe it is healthy and would drink it according to different healthy issues. Chinese people have hundreds or thousands types of soups. We cook them at home and we can find them in restaurants also.
羹 (Geng in Cantonese) usually refers to thick soup such as corn soup, "West Lake Beef Soup", crab meat soup etc. They are usually found in Chinese restaurants which are cooked in a short time like around 10 minutes and are thickened by adding corn starch.
Shark's fin soup (which we don't encourage people to eat nowadays) is one of the few types of soup which can be made in both form.
Then my friend asked. "What about Hot & Spicy Soup?"
"Hmmm.... it is a thick soup but we call them as 湯(Tong)... Consider it as a special case..."
Tips: Therefore when you are ordering in a Chinese restaurant, try to look for the two "Soup" words from the menu. That may help you find the one you like better. You may not understand why they call the soup as "West Lake", but at least you will know probably it is a thick soup if it has the "羹".