The forward DNS service provides name-based identification and access to the various components accessible on an internet, by supplying a destination IP address.

These components to be addressed are individual hosts, particular interfaces on a network, services accessible for end users and the like.

This service provides the translation of numeric IP addresses (IPv4 or IPv6) back to meaningful names for “human consumption”, as well as for debugging tools and some (weak) security facilities.

Reverse DNS is some sort of “inverse” function to the forward DNS service, although the information returned upon a particular reverse DNS lookup is not necessary consistent with the content of the corresponding forward name.

Depending on the point of view, this can be seen as a flaw or as a necessary degree of freedom in managing an internet.