The DNS records which point the IP address to the appropriate hostname.
DNS Pointer resource record. Used to enable special names to point to some other location in the domain tree. Should refer to official (canonical) names and not aliases. See also in-addr.arpa.
A DNS Pointer resource record used to enable special names to point to some other location in the domain tree. They are used in in-addr.arpa records for translation of addresses to names. PTRs should refer to official (canonical) names and not aliases.
Pointer record. A DNS resource record that maps an IP address to a (fully qualified domain) name. Often referred to as a reverse lookup record.