A cookie is a small piece of data that a server sends to a user’s web browser, which the browser may store and send back to the server with subsequent requests. Here are some key points about cookies:

1. Purpose: Cookies are used to remember stateful information, track user activity, and manage sessions on websites.

2. Structure: A cookie typically consists of a name, value, expiration date, path, domain, and security flags (such as HttpOnly and Secure).

3. Expiration: Cookies can be set to expire at a specific date or after a certain amount of time. Session cookies expire when the browser is closed, while persistent cookies remain until their expiration date.

4. Security: Cookies can be marked as HttpOnly to prevent client-side scripts from accessing them and Secure to ensure they are only sent over HTTPS connections.

5. Types:

   • Session Cookies: Temporary and deleted when the browser is closed.
   • Persistent Cookies: Remain on the device until they expire or are deleted by the user.
   • First-Party Cookies: Set by the website the user is visiting.
   • Third-Party Cookies: Set by a domain other than the one the user is visiting, often used for tracking and advertising.

Table of Contents

Use Cases

• Session Management: Track logged-in users and manage their sessions.
• Personalization: Remember user preferences and settings.
• Analytics and Tracking: Monitor user behavior and gather analytics data.
• Advertising: Deliver targeted advertisements based on user activity.

Cookies play a crucial role in maintaining state and enhancing the user experience on websites.