How can the PHP function session_unset() be used to manage session variables effectively in a web application?

When managing session variables in a web application, it is important to properly unset or destroy session variables when they are no longer needed to free up memory and maintain security. The PHP function session_unset() can be used to unset all registered session variables, effectively clearing the session data. This can be useful when a user logs out of an application or when certain data needs to be reset during a session.

// Clear all session variables
session_unset();