backendlisted

# Backend Development — CodeSensei Teaching Module ## What is a Backend? - **Analogy:** If your website is a restaurant, the frontend is the dining room (what customers see) and the backend is the kitchen (where the real work happens). The backend stores data, processes requests, handles logins, and talks to databases. - **Key insight:** The backend runs on a SERVER (a computer somewhere in the cloud), not in the user's browser. ## Servers - **Analogy:** A server is like a receptionist. It sits there waiting for requests ("I want to see the homepage" or "save this form data"), then responds appropriately. - **Express.js** is the most common server framework in vibecoded projects. It's like a template for building that receptionist — you tell it "when someone asks for X, do Y." ## Routes / Endpoints - **Analogy:** Routes are like departments in a company. `/api/users` is the Users department. `/api/products` is Products. Each one handles specific requests. - **HTTP Methods (the verbs):** - `GET` — "Give me data" (reading) - `POST` — "Here's new data, save it" (creating) - `PUT`/`PATCH` — "Update this existing data" (editing) - `DELETE` — "Remove this data" (deleting) - **Quiz:** "If someone fills out a signup form, which HTTP method sends their data to the server?" ## APIs (Application Programming Interfaces) - **Analogy:** An API is a menu at a restaurant. It lists what you can order (available requests), what you need to provide (required data), and what you'll g