Security Basics Study Note PDF
A beginner-friendly Security Basics PDF guide covering JWT, OAuth, CORS, and rate limiting for modern web applications and APIs. This guide explains how real applications authenticate users, authorize API access, protect browser-based requests, and prevent abusive traffic. It is designed for backend, frontend, and full-stack developers who want practical API security fundamentals without getting overwhelmed by advanced cryptography or compliance theory. Topics Covered 1. Authentication vs Authorization - Identity, permissions, sessions, access tokens, refresh tokens, and API protection. 2. JWT - JWT structure, claims, signature validation, expiry, issuer, audience, scopes, and common mistakes. 3. OAuth - OAuth roles, authorization code flow, PKCE, scopes, access tokens, and refresh tokens. 4. CORS - Origins, preflight requests, CORS headers, credentials, allowlists, and common browser errors. 5. Rate Limiting - Fixed window, sliding window, token bucket, Redis counters, 429 responses, and abuse prevention. 6. Real API Security Flow - How JWT, OAuth, CORS, and rate limiting work together in production APIs. What You Will Get 12-page detailed PDF guide API security explanations Real-world examples and code snippets Tables and checklists Common mistakes to avoid Interview Q&A and revision notes Best For Backend developers, full-stack developers, frontend developers working with APIs, software engineering students, API interview aspirants, and developers learning web security basics.
