What are PHP sessions used for

PHP sessions are used to store information about a user across multiple pages. They allow developers to maintain state and track user activity, even after a page reload or navigating to a different page. Sessions are particularly useful for user authentication, storing user preferences, and maintaining a shopping cart during an online shopping experience.

When a session is started, PHP generates a unique session ID for that user which is stored on the server. This ID is sent to the user's browser as a cookie, allowing the server to retrieve the stored session data whenever the user makes a request.