🔤 J - JWT 🔒

JWT stands for JSON Web Token 
It is used for secure authentication and authorization 🔐

In simple words 
JWT is a digital token 
That proves the user is already logged in 🧠

Without JWT ❌ 
• User must login again and again 
• APIs cannot verify identity 
• Sessions become harder to manage 

🧠 What JWT Contains
• Header – token type and algorithm 
• Payload – user data 
• Signature – verifies token integrity 

🔄 How JWT Works
User logs in 👤 
Server creates a JWT 🪙 
JWT is sent to client 📩 
Client sends JWT with every request 🔁 
Server verifies JWT before giving access ✅ 

🌍 Real World Usage
• Login systems 
• Protected APIs 
• Role based access 
• Mobile and web applications 

💻 Example: Creating JWT in Node

const jwt = require("jsonwebtoken");

const user = { id: 1, role: "admin" };

const token = jwt.sign(user, "secret_key", {
  expiresIn: "1h"
});

console.log(token);