REST is not only a brand-new architecture, but also a brand-new way of thinking in the process of Web development: designing system structure through URL. In REST, all URLs correspond to resources. As long as the URL is well designed, the system structure it presents is also good. This is similar to TDD (test-driven development). Through the interface of test case design system, each test case represents a series of requirements of users. Developers don't need to write functions at the beginning, they just need to show the functions that need to be realized in the form of test cases. This is similar to the way of designing system structure through URL in REST. We just need to design a reasonable URL according to our needs. These URLs don't have to link to the specified page or complete some behaviors, as long as they can intuitively show the user interface of the system. According to these URLs, we can design the system structure conveniently. From the concept of REST architecture, everything that can be abstracted into resources can be designated as a URL. What developers need to do is how to abstract user requirements into resources and how to extract images accurately. Because the more accurate the abstraction of resources, the better the application of REST. This is very different from the traditional action-based MVC development model. Well-designed URL can not only make developers know the system structure more clearly, but also facilitate users to remember and identify resources, because URL is simple and meaningful enough. According to the previous design pattern, many URLs are followed by a bunch of parameters, which is also very inconvenient for users.