Every website starts with a domain and a name. A record must verify that the domain has an IP address when you acquire these. The record is called a Domain Name System (DNS) record. In addition to the IP address and domain name, DNS records are associated with information such as TTL (time to live), class (usually IN for internet), and different DNS record types.
The 4 DNS Record Types
The most common DNS record types are A, AAAA, CNAME, and MX.
1. DNS A Record: The Address Mapping record (or DNS host record) stores a hostname and its corresponding IPv4 address.
When users search for your website, the A record redirects this traffic from the web address (xxxxx.com – human-readable domain) to the IPv4 address.
2. DNS AAAA Record: The IP Version 6 Address record also stores a hostname but points the domain to its corresponding IPv6 address. IPv4 and IPv6 differ in the length of the IP address name from 32 bit to 128 bit consecutively.
Since many domains use domain registrars whose nameservers have an IPv4 address, no AAAA record is present. Note that smartphones prefer IPv6, if available.
3. DNS CNAME Record: The Canonical Name record can be used as a hostname alias that points to another domain or subdomain but not to an IP address.
When DNS clients request a record containing a CNAME pointing to another hostname, the DNS resolution process repeats with the new hostname.
4. MX Record: The Mail Exchanger record indicates an SMTP email server for the domain. This record routes outgoing emails to an email server and should not deliver emails to an IP address. One must have MX records configured to receive mail to your domain.