Definition: The default logout.php function in a PHP application is a common way to log out the current user session without prompting them for their credentials. It's a convenience feature used when the login page prompts for login information but no credentials are provided, such as on mobile devices or in non-secure environments where no password can be remembered. In simple terms, it allows the browser to automatically close the logged-in user's browser window after 10 minutes, making the logout process unnecessary.