Looking for information about what DNS (Domain Name System) is, then know that it is a system that facilitates all communication between men and machines.

We human beings use names to identify ourselves, while computers use numbers, and the DNS appears in the middle ground to combine names with numbers that are within an exclusive list.

So, let's learn what the Domain Name System is and how it works?

What is DNS?

It is a system of databases that are distributed over a network in which the main function is to translate the request for some hostnames, to then access specific IP numbers that only the computer(s) understands.

So the information about the hostnames, combined with specific numbers, are all kept in a directory, and that in turn these directories are stored on domain name servers.

How it works?

Now that you already know what it is, it is also very important that you know how it works, it basically works in steps, and within a structure of groups of the Domain Name System. The first steps start with a DNS Query. That this is a query request for some information.

Let's assume that you are surfing the internet looking for something or some information, and of course using a browser for that. Then in the browser you will type the name of a domain, for example www.placardefutebol.com.br.

So at the beginning of the process, a DNS server will look directly at the filehost, which is a simple text file, which is part of the operating system and is responsible for mapping hostnames to IP addresses.

If it does not find any information, it goes directly to the cache, which is hardware or software that stores information temporarily.

The most common places to cache data are certainly Internet browsers, as well as Internet Service Providers (ISP). And the result of this simple step will then obviously be an error message if no data or information is available.

What are DNS Servers?

In a very objective way, we can tell you that a DNS server is a computer, where it has a database, containing public IP addresses, and also their respective associated domains.

We cannot fail to mention that there are many of them, they in turn run software and also communicate with each other based on special protocols.

In short, they are responsible for making the connection between a domain and an IP number, which is the identification of the server where the domain is pointed. So we can say that a DNS server is the system responsible for translating the website “dominio.com” to an IP address.

Know some types of DNS servers:

Now that you know what it is, how it works and what DNS servers are, we have prepared a brief list of some servers below:

Discursive DSN:

Imagine a case where a query (request) is sent repeatedly, so in this case a server can ask other servers to fulfill the request on behalf of the client, which is the browser.

This is known as Recursive DNS. It works something like this: imagine it as if it were an agent that in turn works hard to get each request for data and information answered. So the effort made to get this information also includes calling for help from the Root DSN Server.

Nameserver TLD:

When you need to access the Facebook site, or Google for example, then you end up accessing a domain that ends with the .com extension at the end. Know that this type of extension is also classified as high level.

So, a server for this type of domain is called a TLD Nameserver, and he in turn is responsible for doing all the management of all kinds of information from common domain extensions.

Thus, when requesting information about the www.facebook.com website, the .com TLD will respond to the request for a DNS resolver, thus referencing an Authoritative DNS Server. Also known as Authoritative Name Server. And know that this is the only server that has original resources for this domain.

Root Nameserver:

The Root DSN Server, also called the Root Nameserver, is the highest level of all when it comes to the DNS hierarchy. It has no formal name, and is titled as a simple implied empty line. Try to imagine it as if it were a reference bank, maybe that way you will understand better.

In practice, even the Recurrent DNS will forward the access request to the Root Nameserver, where the server will then respond to the request, and will even inform the agent to go to even more specific locations. That they are the names of high-ranking and TLD-type domains.

Authoritative Nameserver:

Know that when a DNS resolves to meet an authoritative nameserver, then that's when everything happens, because the Authoritative Nameserver already has all the data and information of the domain name in which it serves. Then it can simply give a recurring resolver to the IP address which the server in turn found in the registry.

Types of DNS records:

We could not fail to also mention the types of DNS records, which are:

• A (Host): This is a basic record, where you can add a new Host, TTL (Time to Live) and Point To;
• MX (Mail Exchange): This is the record to identify the server that works with your e-mail, where you can add a new Host, TTL (Time to Live) and Point To;
• CNAME (Alias): CNAME is a record that serves as an alias for another domain, where you can also add a new Host, TTL (Time to Live) and Point To;
• TXT (Text): The TXT record is what allows you to have information in text, where you can also put a new Host, TTL (Time to Live) and Point To;
• NS (Nameserver): This is the DNS server record, where you can also add a new Host, TXT Value and TTL (Time to Live);
• AAAA (IPV6 Address Record): This is the A Record, but only for IPV6 protocols, where you can also put a new Host, IPV6 and TTL (Time to Live);
• SRV: This is the record for a specific type of data in a DNS, where you can add a new Priority, Weight, Name, Port, Point To and TTL (Time to Live).

Quick conclusion:

Just to conclude quickly, the DNS is then a database system, which are distributed in a network, in which its main function is to translate requests from some hostnames, to then access some specific IPs that only computers understand .

So the information and data about the hostnames, combined with the specific numbers, are all stored in one directory, and these directories are stored on domain name servers.

And that's it, we're done here making sure you've learned what the Domain Name System, or DNS, is. To the next ?