ARecord

ARecord is a term most commonly associated with the Domain Name System (DNS) and refers to a resource record that maps a domain name to an IPv4 address. In DNS terminology, the record type is designated by the letter A, and a corresponding ARecord stores the IPv4 address information for the host named by the node’s name.

In typical DNS usage, an ARecord includes fields such as the domain name, the record type (A), the time-to-live (TTL) value, and the IPv4 address. Zone files express ARecords in a compact textual format, for example: www.example.com. 3600 IN A 93.184.216.34. When queried, resolvers return the IPv4 address contained in the ARecord, enabling the client to establish a connection with the host. ARecords are distinct from AAAA records, which map hostnames to IPv6 addresses.

ARecords play a central role in normal web and network traffic, providing the essential link between human-readable domain names and routable IP addresses. They coexist with reverse DNS and PTR records, and they may be cached by resolvers to improve performance. DNSSEC can be used to protect the integrity of ARecords by signing DNS data, although deployment varies by region and domain.

In programming and data modeling contexts, some libraries or systems define a data type or class named ARecord to represent an A-type DNS record. Such a structure typically includes fields for the host name, TTL, and the IPv4 address, and can be used when parsing, generating, or manipulating DNS data in software, DNS utilities, or configuration tools.

Overall, ARecord remains a foundational element of DNS, providing the direct mechanism by which domain names resolve to IPv4 endpoints.