One of the most common tasks in modern web frameworks is to ease the task of writing bits of code that are then called by the framework when a certain URL is hit. How do frameworks do this? What are the most common approaches to interpreting the URL? Understanding how the framework interprets the URL’s to find code to call helps us gain a deeper insight into web frameworks in general. This meta-knowledge of how web frameworks operate allows us to easily move between frameworks in Python, and even other languages.