Frontend and backend

The usual way of dividing different services is by talking about the "frontend" and the "backend." They describe the layers of software, where the layer closer to the end user is the frontend, and the one behind is the backend.

Traditionally, the frontend is the layer that takes care of the presentation layer, next to the user, and the backend is the data access layer, which serves the business logic. In a client-server architecture, the client is the frontend and the server is the backend:

Figure 2.4: Client-Server architecture

As architectures grow more complex, these terms become somewhat polysemic, and they are usually understood depending on the context. While frontend is almost always understood as the user interface directly, backend can be applied to multiple layers, meaning the next layer that gives support to whatever system is being discussed. For example, in a cloud application, the web application may use a database...