DNS Record Types Explained

What is DNS

How does a browser know where a website lives? When a user types google.com, the browser needs an IP. This is where DNS comes into play, DNS solves the problem by helping the browser find the exact IP of the website. DNS is basically a phonebook of the internet. A regular phonebook has names of the people along with their phone numbers while the DNS has IP addresses corresponding to their domains. It converts names into IPs.
Examples: google.com → 142.XXX.XXX.XXX

Why DNS Records Exist

Usually, one domain name is used for several services like websites emails, verifications, etc. DNS records are used in this context. DNS records tell the internet what does what. There are several types of DNS record like A, AAAA, NS, CNAME, MX, etc. All of these records have different use cases and they are used separately to delegate their services using the same domain name. Each DNS record solves one specific problem.

NS Record:

NS record is a type of DNS record that specifies which servers are managing a domain’s DNS records. It is used to navigate traffic to the correct website or application. It informs DNS system which servers hold the IP address. NS records are great for delegating subdomains to specific name servers. They are managed by DNS hosting providers. They contain the domain name, the record type (NS), and the hostname of the name server such as ns1.example.com. NS records tell the internet which DNS server is in charge.

A Record:

A record is the fundamental alternative to human-readable domain names like google.com. A record converts a domain name to IPv4. It directs traffic to the server hosting the website, allowing users to access sites using domain names rather than complex IP addresses. The main purpose of A records is to point a domain to an IP address. It is specifically used for IPv4, while AAAA is used for IPv6. A domain can have multiple A records, which are often used for load balancing, where traffic is distributed across different servers. This is the most important record for websites.
Example: example.com → 93.184.216.34

AAAA Record:

Exactly the same as A but IPv6. IPv4 maps to 32 bit-IPv4 addresses while AAAA records map to 128bit-IPv6. A records are the standard for older networks, whereas AAAA records are required for modern IPv6 connectivity and faster networking.

CNAME Record:

CNAME record is short for Canonical Name, it is a type of DNS that maps an alias domain or subdomain to a canonical domain name, rather than directly to an IP address. It is essential for mapping subdomains to external services and simplifying DNS management when updating IP addresses. CNAME records must point to a domain name, never directly to an IP address. When a user visits a CNAME site, the DNS resolver looks up the target domain to find the final A record, which provides the IP address.

MX Record:

MX which stand for Mail Exchange is a type of DNS record that is used to reroute incoming mails to the correct mail server for a domain. It is used for email delivery, directing messages to specific servers like Microsoft 365 or Google workspace. The MX record indicates how email messages should be routed in accordance with SMTP(Simple Mail Transfer Protocol).

TXT Record:

A TXT record is a DNS record that stores human-readable or machine-readable text about a domain. It doesn't tell a computer where to go like an IP address, but instead holds text-based information for verification and security. It is essentially used for keeping notes that can be used to prove services like Google that you actually own the website or provide a list of "approved senders" to stop spammers from faking emails from your domain.

How all DNS records work together for one website

The NS Record is the city directory. It tells the world exactly which map to look at to find the building. Once you have that map, the other records guide the traffic:

• A Record (The Address): This guides browsers to the main front door which is the IP Address so they can enter the building.

• CNAME (The Redirection Sign): If someone asks for www, this sign says, "That is just the main building," and points them back to the A Record. It is a redirection for the same location.

• MX Record (The Mailroom): This tells postman to skip the front door and deliver letters to the back gate.

• TXT Record (The Security Badge): This is a public notice on the wall used for verification. It proves who owns the building and lists who is allowed to speak on its behalf.