Like a letter in the post office, an address or coordinate is needed to locate a website in the world of the internet. A domain name system, also known as DNS, is the internet's answer to the Post Master. This article will explain the various parts of DNS and how each record type has a purpose.
Nameservers, also referred to as NS records, are the primary records in DNS that make an IP address answer back to a domain name on a server. If it weren't for nameservers, people would need to use IP addresses to pull up websites rather than a domain name, which would make web addresses a lot harder to remember.
For example, say the IP address:
Resolves to the domain:
Address records, also known as A records, are the other side to nameservers. Address records point a domain to an IP address on a server, making it resolve to a specified IP address.
Canonical Name records, better known as CNAME records, serve as aliases for domain names of another canonical domain name. This normally works best for pointing domains with a subfolder to a subdomain under the same primary domain name.
Mail Exchange records, also known as MX records, are the primary records which direct email for a domain name. These records work in conjunction with the A records and NS records to direct the email received for a domain name to the proper mail server. Usually, MX records are prioritized with a number of preference that will indicate which mail servers should be used when there are several listed.
Reverse DNS records, also known as pointer or PTR records, are used to resolve IPs to a domain name and vice versa. That means you can make sillydomain.com point to 10.0.0.1, and make a ptr record so that 10.0.0.1, if checked, would tell you that it belongs to sillydomain.com. It also allows the receiver of your emails to check for possible spoof emails which will be treated as spam. Without this record, the receiver must rely on guessing if your email might be spam.
Text records, better known as TXT records, are custom records which contain human-readable data. TXT records are dynamic and can be used for several purposes such as verifying domain ownership for services such as Google Apps.
Service records, also known as SRV records, are used to point one domain to another domain name using a specific destination port. SRV records allow specific services, such as VOIP or IM, to be be directed to a separate location.
An AAAA record points a domain or subdomain to an IPv6 address in the same way that an A record does; however, A records use IPv4 addresses only. Currently, we do not support IPV6 addresses.