DNS Records or Zone files are the instructions that live in authoritative DNS servers and provide information about a domain, including what IP address is associated with that domain and how to handle requests for that domain.
These records consist of a series of text files written in what is known as DNS syntax.

DNS syntax is just a string of characters used as commands that tell DNS servers what to do.

All DNS records also have a TTL, which stands for time to live, and indicates how often a DNS server will refresh that record.

Most common types of DNS records

A Record: The record that holds the IP address of a domain. A Stands for “address” and this is the most fundamental type of DNS record: it indicates the IP address of a given domain.

Example:

AAAA Record: AAAA records match a domain name to an IPv6 address. DNS AA records are exactly like DNS A records, except that they store a domain’s IPv6 address instead of IPv4 address

Example:

0000:8a2e:0370:7334 | 14400 |

CNAME Records: A “Canonical Name” (CNAME) records points from an alias domain to a canonical domain. A CNAME record is used in lieu of A record, when a domain or subdomain is an alias of another domain. All CNAME records must point to a domain, never to an IP address.
A frequesnt misconception that CNAME reecord must always resolve to the same website as the domain it points to, but this is not the case. The CNAME records only point the client to the same IP address as the root domain.
Example:

MX Records: A DNS ‘mail exchange’ (MX) records direct email to a mail server. the MX record indicstes how email messages should be routed in accordance with the simple mail transfer protocol(SMTP). and it proceesd by MTA(message transfer agent) which responsible for querying the MX records, ex: when a user sends email, the MTA sends a DNS query to identufy the mail servers for the email recipients. The MTA establishes the connection wuth those mail servers, starting with the prioritized domains.

Example:

NS Record: NS stands for ‘name server’, and the nameserver records indicates which DNS DNS server is authoritative for that domain. Besically NS records tell the internet where to go to find the a domain’s IP adress. A domain has multiple NS records which can indicate primary and secondary name servers for that domain. Users won’t be able to load websotes/application without configuring NS properly.

Example:

TXT Recods: The DNS TXT record lets domain administrator enter text into the Domain NAme System. The text stored in the form of one or more strings whithin quotation marks. The TXT record was originally intended as a place for human readable notes. However, now it is alos possible to put some machine-redable data into TXT records. One domain can have mant TXT records.
Eg;