DNS refers to the Domain Name System used on the internet. DNS is the system that matches domain names to an IP address. For a domain name to be used on the internet it has to resolve to a specific IP address. DNS is similar to a map or telephone white pages in as much as [for example] when you type a website domain name into your web browser address bar it is DNS that “tells” your web browser “that website is being hosted at *this* IP address” and then your web browser sends a request to the IP address to deliver the website data.
There are many DNS web servers on the internet. When a domain DNS settings change it can sometimes take up to 36 hours for the information to refresh on all DNS web servers throughout the internet. Some DNS web servers may refresh fairly quickly and regularly, for example the Google DNS web servers. Other DNS web servers, for example a local ISP that refreshes their DNS web servers once a day, might take longer.
DNS settings are entered when setting up a dedicated server in order to “tell the internet” how to reach it. In that respect, the IP address[es] assigned to a dedicated server, VPS, or individual website is similar to the street address of a house. DNS settings are the “central telephone book” of the internet that says “when you are looking for that street address it is located here” It is because of DNS that you don’t have to remember the IP address of each website that you would like to visit. Instead, you only have to remember the domain name, and then “behind the scene” DNS directs the domain name to the IP address where it is hosted for you.
