DNS (Domain Name System) associates various information with domain names to different services. Using DNS is like using the phone book, where you would look up a phone number, type it in and get directed to its location.
Here are some common examples of DNS records:
- A record or address record maps a hostname to its 32-bit IPv4 address.
- CNAME record or canonical name record makes one domain name an alias of another. The aliased domain gets all the subdomains and DNS records of the original.
- MX record or mail exchange record maps a domain name to a list of mail exchange servers for that domain.
- NS record or name server record maps a domain name to a list of DNS servers for that domain. Delegations depend on NS records.
- SOA record or start of authority record specifies the DNS server providing authoritative information about an Internet domain.
- SRV record is a generalized service location record.
- TXT record allows an administrator to insert arbitrary text into a DNS record. For example, this record is used to implement the Sender Policy Framework specification.