Client–server applications already existed back in Web 1.0.
The reason we moved toward doing programming in places other than just the server is because the technology changed. The network changed. People started using mobile devices. All of that shifted how we build things. So the classic client–server application, where everything happens on the server, is really more of a Web 1.0 kind of model.
Because of that, a lot of the web‑framework tooling you see in traditional programming classes focuses primarily on presentation. You do the programming, and then the “web part” is mostly about displaying it. We’ll cover some of that here, but for us, it’s not just about presentation anymore.