A DNS record, also known as resource record or simply RR, has specific rules in a DNS zone. The DNS records are completely made of text. That makes them very light. Those written instructions are stored inside zone files. There are forward lookup DNS zones, Reverse lookup DNS zones, Primary DNS zones, and Secondary DNS zones. They can host different recourse records.
Depending on the request, the DNS servers start searching for a specific type of DNS record like an A DNS record that points a hostname to an IP, MX for accepting mail messages, another hostname, or a particular service of a hostname.
As we mentioned before, the DNS records are just text, so they are easy to edit. Please pay attention when you are changing any parameter on them, because that can lead to incorrect redirection or not responding service.