What are the main features of using cookies?

• Client-side data storage: Cookies are stored in the user's browser.
• Sent with each request to the server: With each request to the domain that set the cookie, it is automatically sent via the Cookie HTTP header.
• Size limit: The size of a single cookie is usually limited (often 4KB), and there is also a limit on the total number of cookies per domain.
• Lifetime: The lifetime of a cookie is set when it is created (Expires or Max-Age) or it exists until the browser is closed (session cookie).
• Security:
  • HttpOnly: Prevents access to the cookie from JavaScript, protecting against XSS attacks.
  • Secure: Sends the cookie only over HTTPS connections.
  • SameSite: Controls the sending of cookies with cross-site requests, preventing CSRF attacks.
• Management: Cookies can be managed on the server side (via the Set-Cookie header) and on the client side (via document.cookie), if the HttpOnly flag is not set.
• Usage: Sessions, personalization, activity tracking.

// Getting all available cookies
const allCookies = document.cookie;

// Setting a new cookie
document.cookie = "username=John Doe; expires=Thu, 18 Dec 2023 12:00:00 UTC; path=/";

// Deleting a cookie (setting expiration in the past)
document.cookie = "username=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/";