Compared with hot dishes, cold dishes are basically the same except for the preliminary processing of raw materials. The obvious differences are as follows: the former usually cooks first and then cuts; The latter is to cut first and then cook. Hot dishes generally adopt the natural form of raw materials or the cutting, processing and copying of raw materials to form the shape of dishes; Cold dishes take silk, strips, slices and blocks as the basic units to form the appearance of dishes. The cold dishes with high technological names include single dish, mixed dish and flower-and-bird pattern.