Domain Name System (DNS) translates domain names, like IPSearch.io, into IP addresses such as 147.122.10.6. Without DNS online users would need to memorize IP addresses to access websites or other online services accessible by name. This would be especially hard for IP6 addresses, which are much longer than IP4 addresses.

DNS was created in 1983 by Paul Mockapetris, a computer scientists at Southern California's Information Sciences Institute (USC-ISI). Before the creation of DNS, a central hosts.txt file was required to translate a domain name to an IP address. The creation of DNS made this activity more scalable and efficient.

There are different types of DNS records that serve different purposes. Some record types will translate domain names to IP addresses and others will provide other information about a domain. Below is a command list of DNS record types.

DNS Record Types:

• A Record (Address Record): Maps a domain name to an IP4 address
• AAAA Record (IPv6 Address Record): Maps a domain name to an IP6 address
• CNAME Record (Canonical Name Record): An alias that points one domain or sub domain to another
• MX Record (Mail Exchange Record): Specifies the mail server for the domain
• NS Record (Name Server Record): The name server responsible for the domain
• PTR Record (Pointer Record): Maps an IP address to a domain name for reverse DNS lookup
• TXT Record (Text Record): Texts records that are often used to validate the domain with another service
• SRV Record (Service Record): Indicates that server for a service
• SOA Record (Start of Authority Record): Shows details for the domain and zone
• CAA Record (Certification Authority Authorization Record): Provides a list of CA's that are allowed to issue certificates for the domain

DNS records are updated by the domain owner using the interface provided by the registrar. The registrar is the organization that holds the registry for the domain. The registry is commonly the website the domain owner registered the domain but domains can also be transferred from one registrar to another.

Updated DNS records for a website is not a very technical task. DNS records are typically updated using a web interface but domain owners will need to validate the accuracy of their update. Updated DNS records are one of the first task any website owner will need to complete.

When an user types in a web address there is a process that occurs behind the scenes to resolve the domain and direct the request to the correct server.

1. DNS Query: The DNS resolver checks the cache on the local device to see if a recent answer exists
2. Query to Recursive Resolver: The recursive resolver is checked if no answer is cached
3. Query to Root Name Server: The root name server will send the request to the appropiate TLD server (eg. .com, .net, .io)
4. Query to TLD Name Server: The TLD server sends the address of the name server
5. Query to Authoritative Name Server: The authorization server queries the name server, which responds with the IP address of the domain
6. Returning the IP Address: The recursive resolver sends the IP address back to the device attempting to access the website
7. Access the Website: The web browser uses the IP address to access the website