Also called an A record, a type of resource record in the Domain Name System (DNS) that maps the name of a host computer or other network device to an IP address.
Address records enable resolvers to query a DNS server on the network in order to resolve a host name or fully qualified domain name (FQDN) of a machine into its IP address so that network communication with the machine can be established. Address records are one of the most commonly used types of resource records stored in DNS zone files.
A large part of the administrative work of a DNS administrator is creating and maintaining accurate address records for hosts on the network. The syntax for the address record is specified in Request for Comments (RFC) number 1035.
An address record for the host named SERVER12 located in the northwind.microsoft.com Internet domain and having the IP address 172.16.8.55 would be
server12.northwind.microsoft.com IN A 172.16.8.55
Here IN identifies the record as belonging to the Internet class, and A identifies that it is an address record.