A brief overview of HTTP cookies and their usage.
Cookies are small pieces of data that a server sends to the user's web browser. The browser may store it and send it back with subsequent requests to the same server. They are primarily used for session management (like keeping a user logged in), personalization (storing user preferences), and tracking (recording user behavior). In JavaScript, you can interact with cookies via the `document.cookie` property. However, this API is quite primitive and can be awkward to work with directly, as it treats all cookies as a single string. You typically have to parse this string to read a specific cookie and construct a formatted string to write one, including attributes like `expires`, `path`, and `secure`. While it's good to understand how they work, in modern web development, `localStorage` and `sessionStorage` are often preferred for client-side storage because of their simpler API and larger storage capacity. Cookies are still essential for certain tasks, especially those involving server-side authentication and tracking across different browsing sessions, as they are automatically sent with every HTTP request to the relevant domain.