revision:
Back-end development for a webpage refers to the server-side work that powers the website's functionality, data management, and logic. It involves everything that happens behind the scenes to ensure the front-end (what users see and interact with) works properly.
1. server:
The server is the backbone of the back-end : it handles requests from the client (browser), processes them, and sends back the appropriate responses.
Examples of server technologies: Apache, Nginx, Microsoft IIS.
2. database:
Databases store and manage the data used by the website (e.g., user information, product details, etc.).
Common databases: MySQL, PostgreSQL, MongoDB, SQLite, and Redis.
3. application logic:
This is the core programming that defines how the website functions. It includes handling user requests, processing data, and managing business logic.
Popular back-end programming languages: Python, PHP, Ruby, Java, JavaScript (Node.js), C#, and Go.
4. APIs (application programming interfaces):
APIs allow communication between the front-end and back-end, or between different systems. They define how data is requested and exchanged.
Examples: RESTful APIs, GraphQL.
5. autentication and authorization
Back-end developers implement systems to verify user identities (authentication) and control access to resources (authorization).
Tools: OAuth, JWT (JSON Web Tokens), and session management.
6. security:
Back-end developers ensure the website is secure by protecting against threats like SQL injection, cross-site scripting (XSS), and data breaches.
Practices: encryption, input validation, and secure authentication.
7. performance optimization
Back-end developers optimize the server and database to ensure the website runs efficiently, even under heavy traffic.
Techniques: caching, load balancing, and database indexing.
Python : Django, Flask
JavaScript : Express.js (Node.js)
Ruby : Ruby on Rails
PHP : Laravel, Symfony
Java : Spring Boot
C# : ASP.NET
1. A user submits a form on the front-end (e.g., login credentials).
2. The browser sends a request to the server.
3. The back-end code processes the request, checks the database for the user's credentials, and verifies them.
4. The server sends a response back to the front-end (e.g., "Login successful" or "Invalid credentials").
5. The front-end updates the user interface based on the response.
When using Node.js in a web project, it's important to understand that Node.js runs on the server , not directly in the browser.
Your client-side files (HTML, CSS, JavaScript) are served to the browser, while Node.js files handle server-side logic, APIs, or backend services.
A typical "Node.js" web project structure might look like this:
your-project/
├── server.js # Main Node.js server file (entry point)
├── package.json # Node.js dependencies and scripts
├── public/ # Static files (HTML, CSS, JS, images, etc.)
│ ├── index.html
│ ├── styles.css
│ └── script.js # Client-side JavaScript
└── node_modules/ # Installed Node.js modules (auto-generated)
Server files (e.g., server.js, app.js, or API routes) go in your project's root directory (not inside public).
Client-side files (HTML/CSS/JS) go in the public folder (or a subfolder like public/js, public/css).
Use a Node.js framework like "Express.js" to serve your static files (HTML, CSS, JS) from the public folder.
Example:
// server.js (Node.js server)
const express = require('express');
const app = express();
const path = require('path');
// Serve static files from the "public" directory
app.use(express.static(path.join(__dirname, 'public')));
// Start the server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Server running on http://localhost:${PORT}`);
});
Place your browser-specific JavaScript (e.g., script.js) in the public folder. Link to it in your HTML file:
<!-- public/index.html -->
<script src="/script.js"></script>