What is the function of the eaves to receive water?

Didi is a kind of roof in the past. The joint between the roof and the external wall is used to drain the rainwater from the roof and prevent the rainwater from flowing to the external wall. Buildings in ancient China are generally brick and wood structures. If it is eroded by rain, it will not only grow mildew, but also harm buildings. I wish the walls of modern high-rise buildings were waterproof. . . . Dripping bricks and Chinese tiles can protect the cleanliness of the wall. One end has a drooping edge, the bottom tile is at the cornice, and the lower end has a drooping round pointed tile, which is placed at the cornice when the roof is built, and the lines of plants or flowers will be painted before firing. Nowadays, "dripping water" is often regarded as an art with appreciation value in architectural construction.