How to distinguish utility model patents from invention patents?

1, the definition of patent law is different: invention: technical scheme with high degree of innovation, significant improvement or significant technical significance; Utility model: For products with certain structure and construction, the improvement should only have corresponding functional effects. 2. The application process is different: the invention review is strict, and preliminary review and substantive review are needed. The utility model can only pass the preliminary examination. 3. Different protection periods: the invention is valid for 20 years and the utility model is 10 years.