What are sessions and cookies in PHP? How are they used for managing user sessions?

Sessions and cookies are essential components of managing user sessions in PHP. They help maintain stateful interactions between the server and client, allowing web applications to recognize and remember users across multiple requests. Here's an in-depth explanation of sessions and cookies in PHP and their role in managing user sessions: 1. Sessions: * Sessions are a server-side mechanism used to store and manage user-specific data during a user's visit to a website. * When a user accesses a PHP-based web application, a unique session is created on the server to track the user's interactions. * A session identifier, often stored in a cookie or passed through the URL, is used to associate subsequent requests from the same client with the corresponding session data on the server. * Session data is stored on the server and can include information such as user preferences, shopping cart contents, or authentication status. * Sessions typically expire after a certain period of inactivity or w....