The Cantonese word Yum Cha refers to drinking tea and eating dim sum at a restaurant. Dim sum (Dianxin in Chinese) is a style of Guangdong (Cantonese) food prepared as individual portions served in small round bamboo baskets or on small plates.

Customers choose from different fully cooked dishes that servers push on carts around the restaurant, and customers can choose their dishes while seated at their tables. Each dim sum dish is normally served with three to four servings per dish. Because of the small portions, people can try a variety of food. Also, dim sum usually comes with tea (such as jasmine or green tea). Chinese people believe that drinking tea with greasy food burns away some of the fat from your meal.

Facts about Chinese Dim Sum: http://www.chinesecultureshop.com/facts-about-chinese-dim-sum/