Reverse DNS, or rDNS, is the opposite of Forward DNS. Okay... what the heck is Forward DNS then? Forward DNS (Domain Name System) is what allows us to use nice, memorable names for our websites instead of ugly IP addresses. For example, Forward DNS (normally referred to simply as DNS) allows us to type in a nice name like www.ovaleye.com while behind the scenes our browser is actually being pointed to 216.211.143.22. It's all quite transparent.