Internship← Full Stack Web Development learning pathFull Stack Web Development · Module 7 of 10
Authentication and security
Log users in and protect the app.
📖 Key ideas
- Hash passwords (bcrypt/Argon2); never store plain text.
- Sessions (cookies) or JWT tokens identify users.
- OAuth/social login via providers (Google, GitHub) or services (Firebase Auth, Auth0).
- Protect against XSS, CSRF and injection.
- Always use HTTPS and validate on the server.
💡 Real-life example: Authentication is the security desk checking ID; authorisation is deciding which floors you may visit.
AuthenticationVerifying who a user is
AuthorisationDeciding what a user may do
JWTSigned token
OAuthDelegated login standard