Introduction When you log into a website and stay logged in without entering your password again, it is not magic—it is handled by cookies and sessions. Understanding how cookies and sessions work is essential for learning web security, ethical hacking, and penetration testing. This guide explains these concepts in a simple and practical way. What are Cookies Cookies are small pieces of data stored in your browser by a website. They are used to remember user information such as login status, preferences, and tracking data. Key Features of Cookies Stored on the client (browser) Sent with every HTTP request Can store session identifiers Used for tracking and authentication What are Sessions Sessions are server-side storage mechanisms that keep track of a user’s activity. Instead of storing sensitive data in the browser, sessions store it securely on the server. Key Features of Sessions Stored on the server Identified by session ID More secure than cookies Used for authentication ma...