What Is DNS (Domain Name System)

The Domain Name System/Server/Service, or DNS, is a hierarchically partitioned naming convention for computers and services from any source connected to the Internet or to a personal network (TCP/IP). It links various domain name information, including technical functionality. In general, the DNS system handles the conversion of an IP record into a web address and the communication between servers.

As mentioned above, DNS is the “intermediary” in the communication between servers, including users. In addition, it also handles the conversion of these records, since the records on the network are written in IP format (for example: 213.252.693.21 – IPv4), and the DNS server converts these records into a more user-friendly record (for example: mojadomena.si), and in this form they are easier to remember and, of course, easier and simpler to manage.

HOW THE SYSTEM WORKS IN PRACTICE

To begin with, each device on the Internet network has its own unique identification number (IP address), which is used by the devices or services to communicate with each other in order to reach the desired destination. However, to reach your destination, the DNS (domain name system) must properly translate your request and route it towards your destination. Routing takes only a few milliseconds.

You browse the Internet with a browser (Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, etc.) and click on a link (for example in Google search). This starts the following process:

1. Your browser reads the request, writes it to the browser cache and forwards the request to the DNS manager in your operating system (Windows, Linux, OS X, etc.).
2. The operating system forwards the request to your ISP (Siol, Amis, T-2, Telemach, etc.). They have their own cache, which sometimes already contains the address of the final server. If it can’t find the record, it forwards it to the DNS server above it (it usually goes to the registrars – the domain extension issuers).
3. When the request reaches a DNS server that has the IP address of the domain in its cache, it looks up the IP address in its table and returns the corresponding IP (server). The browser then makes a request to this server based on this information and returns the result back to your browser, which displays the requested web page content.

As mentioned at the beginning of this article, DNS works hierarchically and recursively.

The Domain Name System can also be thought of as our, or the world’s, postal system. Similarly to DNS, a mail-packet travels from sender to addressee with intermediate stops in between. We could also say that the postal system filters the mail-packages and delivers them to the right addressee based on our requests. The only difference is that the requests are not filtered and converted by the DNS but by post offices all over the world. So the mail travels recursively (in a certain sequence – a staircase) until it reaches your mailbox or, more and more often, your door.