HowTo Setup a Linux DNS Server - bind9
The DNS (Domain Name System) is a naming system for computers, the service that does that is called DNS server which translates an IP address to human readable address, this process is the backbone of the internet and very important service in your server, so from that point, we will discuss DNS server or specifically Linux DNS server and how to install, configure and maintain it. The config file /etc/hosts Without the need to DNS server, It’s reasonable for each system to keep its own copy of a table of the hostnames on the local network with their corresponding IP addresses especially small sites with no internet connection. In Linux systems, this table is the /etc/hosts file. So even if you don’t have DNS server or DNS server is unavailable this file can translate IP addresses to names using /etc/hosts file. Or maybe you have already DNS server but you want to keep this file for some other reasons. For example, a system might need to look up an IP address locally before going out to query the DNS server That means the system goes for this file first before going to DNS server if it found the domain on it will translate it without going to any DNS servers.