Difference between REMOTE_HOST and REMOTE_ADDR

Question

What is the difference between these two variables?

REMOTE_HOST and REMOTE_ADDR.

Answer 1

1. $_SERVER['REMOTE_ADDR'] - This contains the real IP address of the client. That is the most reliable value you can find from the user.

2. $_SERVER['REMOTE_HOST'] - This will fetch the Host name from which the user is viewing the current page. But for this script to work, Hostname Lookups On inside httpd.conf must be configured.