The similarity between utility model and invention lies in that utility model must also be a technical scheme, not an abstract concept or theoretical expression. The difference between utility model and invention lies in that, firstly, utility model is limited to products with certain shapes, and cannot be methods, such as production methods, test methods, treatment methods and application methods, nor can it be products without fixed shapes, such as drugs, chemicals and cement. Second, the utility model is not too creative, but it is very practical.