Let's talk about websites. Whenever you visit a website, there are two main "types" of applications that you'll interact with: the frontend and the backend.
I've made a little example for you to give you an idea of how a backend server might look (and how the frontend would interact with it). Throughout this unit, we'll be working with both the backend and frontend, but we'll be prioritizing function over form (as you can see, the frontend does not look very good). In practice, you wouldn't make a frontend like this, but you would make a backend like this (and that's what we're focusing on).
Take a look at both the frontend and backend files and see if you can change them around to do something else. We'll go over exactly how everything works later on. Good luck!