Frontend and backend separation

Frontend is the part users see and interact with: screens, buttons, forms, voice interfaces like Alexa or virtual reality using devices like goggles and joysticks. Backend is the system that processes data, runs logic, and stores information. Take Instagram, for example. When you upload a photo, the frontend lets you pick the image and shows a loading spinner. The backend checks the file, compresses it, saves it on servers, and updates your profile.

This split speeds up development, improves run time, and security. Spotify’s front applications on iOS, Android, and web apps all share the same backend. So, if the backend team builds a new feature, every frontend app can use it. If the design team changes the interface, the backend code doesn’t need to change

The connection between them is an API (application programming interface). The frontend sends a request with what it needs. The backend responds with the right data, formatted in a way the frontend understands. That’s how both sides stay in sync without depending on each other’s code.