What is DNS?
Domain Name System or DNS is a phone book of the whole Internet. The users get access to necessary information through the domain names such as google.com and others. Web browsers interact by means of IP protocol. DNS transforms the domain names into IP-addresses so that browsers can download Internet-resources.
Every device connected to the Internet has its unique IP-address which is used by other devices to find it. DNS-servers excused a duty to keep in mind those long IP-addresses like 192.168.1.1 (for IPv4) or even more complex new style addresses - 2400:cb00:2048:1::c629:d7a2 (for IPv6).
How does DNS work?
The process of DNS implementation includes the conversion of the host’s name into the IP-address, i.g. www.example.com will be transformed into 192.168.1.1. To understand the process standing behind the DNS implementation, you need to know the different physical nodes the DNS-query passes through.
4 DNS-servers involved in the web page loading
| DNS recursor | DNS recursor is used to receive queries from client devices through applications like web browsers |
| DNS root server | The root server is the first step in the process of conversion of hosts names into IP-addresses |
| Top-level domain | This DNS-server is the next step in the search of a certain IP-address. It contains the last part of the host’s name. I.g. in the address example.com the top-level domain is “com” |
| Authoritative DNS-server | An authoritative server is the last step of the DNS-query. If such a server has access to the requested record, it will return the IP-address of the requested host to a DNS recursor that made the initial request |