What is the correct method to retrieve the user's browser information in PHP?

To retrieve the user's browser information in PHP, you can use the $_SERVER['HTTP_USER_AGENT'] superglobal variable. This variable contains the user agent string that the browser sends in the HTTP headers, which typically includes information about the browser and operating system being used.

$user_agent = $_SERVER['HTTP_USER_AGENT'];
echo "User's browser information: " . $user_agent;