<aside> 📚 📁 Category: Backend

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Overview

Authentication verifies 'who you are' (identity), while Authorization determines 'what you can do' (permissions). These are fundamental security concepts in modern web applications.

<aside> ℹ️ Why It Matters: Understanding Authentication & Authorization is essential for building robust, scalable, and secure modern applications.

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Key Concepts

• [x] JWT (JSON Web Tokens) - Stateless authentication
• [x] OAuth 2.0 - Third-party authorization framework
• [x] OpenID Connect (OIDC) - Identity layer on top of OAuth 2.0
• [x] Role-Based Access Control (RBAC)
• [x] Multi-Factor Authentication (MFA)
• [x] Password hashing with bcrypt, Argon2, or PBKDF2
• [x] Session management and token refresh strategies
• [x] API Key authentication for service-to-service

Common Use Cases

<aside> 💡 Where to Apply Authentication & Authorization

                        User login/logout systems
                        Protected API endpoints
                        Single Sign-On (SSO) implementations
                        Social media login (Google, Facebook, GitHub)
                        Microservices authentication
                        Mobile app authentication

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Best Practices

• [x] Never store passwords in plain text
• [x] Use HTTPS for all authentication endpoints
• [x] Implement rate limiting on login endpoints
• [x] Use secure, httpOnly cookies for tokens