Cookies

Summary

Small pieces of data a server asks the browser to store and send back on every request — commonly used for sessions, auth tokens and preferences. Because cookies are automatically attached to matching requests, their scope, lifetime, and security attributes directly affect authentication, privacy, and cross-site request behavior.

• 1Inspect cookies for a site you're logged into via DevTools' Application tab. Validate your understanding by applying it in a small practical example.
• 2Learn the difference between session and persistent cookies. Focus on understanding the underlying reason it works, not only memorizing the definition.
• 3Understand HttpOnly, Secure and SameSite cookie flags and why they matter for security.