The <strong>backend</strong> is the part of a system that users don't see. It handles business logic, database operations, authentication, and everything that happens 'behind the scenes' on the server.
The Kitchen of a Restaurant
Customers see the dining room (frontend), but the real work happens in the kitchen (backend).
Frontend
Dining area (what you see)
Backend
Kitchen (where work happens)
Database
Pantry (where ingredients are stored)
Interacts with frontend
Processes logic
Stores data
Receives Requests
Frontend sends user actions to backend
Validates Data
Checks if the request is valid and authorized
Business Logic
Runs calculations, rules, workflows
Database Operations
Reads or writes data as needed
Sends Response
Returns result to frontend
Wrong
Backend is just a database
Correct
Backend is the code that runs on the server. It includes business logic, APIs, authentication, and talks to the database. The database is just one component the backend uses.
When you post on Facebook:
Frontend: You type and click 'Post'
Backend: Validates you're logged in
Backend: Checks post content for spam/violations
Backend: Saves post to database
Backend: Notifies your friends
Frontend: Shows success message