How can you retrieve the browser information in PHP using the $_SERVER variable?

To retrieve the browser information in PHP using the $_SERVER variable, you can access the 'HTTP_USER_AGENT' key within the $_SERVER superglobal array. This key contains the user-agent string that typically includes information about the browser being used to access the webpage. By accessing this key, you can extract and display the browser information in your PHP script.

$browser_info = $_SERVER['HTTP_USER_AGENT'];
echo "Browser Information: " . $browser_info;