How can PHP be used to retrieve the IP address of a user?

To retrieve the IP address of a user in PHP, you can use the $_SERVER['REMOTE_ADDR'] global variable. This variable contains the IP address of the user making the request to the server. By accessing this variable, you can easily retrieve the IP address of the user.

$user_ip = $_SERVER['REMOTE_ADDR'];
echo "User IP Address: " . $user_ip;