https://github.com/bhandarisachindev/NodeBackend Day14

JWT (JSON Web Token) is a secure, compact way to represent user identity and permissions between client and server — often used for authentication.

🧱 Structure of a JWT

A JWT looks like this:

xxxxx.yyyyy.zzzzz

It has 3 parts:

Part	Name	Contains
1️⃣ Header	Metadata	Type of token + algorithm used (e.g., HS256)
2️⃣ Payload	Data	User info, roles, token expiry, etc.
3️⃣ Signature	Verified	Encrypted signature to prevent tampering

🔐 Why JWT is Powerful

Feature	Benefit
✅ Stateless	Server doesn’t need sessions or DB lookups
✅ Self-contained	All info is in the token itself
✅ Tamper-proof	Signature ensures it wasn’t modified
✅ Fast	Lightweight — just a string

🔐 What is a JWT Secret?

The JWT secret is a private key string used to sign and verify JSON Web Tokens (JWTs). It's what ensures that a token is valid and hasn't been tampered with.

https://jwtsecrets.com/#generator

NOTE: Use Only a single JWT key in your app life

✅ Reasons to Use Only One JWT Secret