Blog / What are DNS and the domain records?

What are DNS and the domain records?

by SW Team

icon-gestio-dns400x400From the very first moment when an user types a domain in his browser, its sent a petition that transforms itself in a web page. This petition begins with the DNS identification, establish which are the NS records, as well as where to find the A record, and maybe using a CNAME previously defined.

In this post we will see what DNS are and what roles have the records A, MX, NS and CNAME in the domains system.

The domain is the name that identifies you around the Internet: the address that any user of the net can find and where the website or your company of yours is at: the domain is traceable for all the PC’s connected to Internet.

The mix of numbers named IP address, allows computers to trace the address and find your website. For a computer is very easy to remember endless sequences of numbers, but, how can a user remember all of this? If a user wants to go to SW Hosting headquarters, he just needs to know where Ponent Street in Fornells de la Selva is, and surely he will remember for next visits. But, he would remember the IP address around the Internet  for next visits? He would, with the IP’s translate system: the DNS (Domain Name System) identifies the digits and converts them into a name easy to remember.

As we just saw, the DNS are the translate mechanism of the group of digits that form the IP address of the computer. I.E, every time that an user wants to enter to ‘’, the DNS will translate this to ’59.159.412.66’, as an example.

NS records are the servers’ names that define the DNS. This means that two or more servers will have the information that allows the user’s computer find the domain named ‘’. Minimum it must be two records (i.e, two servers): the first or ‘Master’ and the second, or ‘Slave’. The first server owns all the information about the server’s files while the second one replicates the first server’s information.

Once located the domain, it’s needed the A register to locate the website as well as the web server. To do it, the record gives the IP number where is located the domain.

Meanwhile, CNAME record (or Canonical Name), allows to identify the alias or subdomain, which are equivalent as the domain. For example, ‘’ is the same as ‘’, being the CNAME ‘www’.

Last, the MX record (Mail Exchange) is the one that defines which is the e-mail server for the domain. It can be different MX records, coordinated to priorities.

In SW Hosting, you can modify or create records as you want, with the easiness that proposes the SW Panel and the 51 video tutorials, among which we show you ‘How to assign a Hostnames to domain’ or ‘DNS Management’.