DNS is a set of computers that keep track of every domain name on the Internet.
The DNS system allows you to reach your website using only the domain name (the name of your website). This is called "hosting," and it means that no one can block your website by blocking its IP address (the number that identifies your computer). DNS also allows users to find those websites by entering their domain name in the search bar.
Domain Name System (DNS): What It Is and How to Set It Up
DNS is the backbone of the internet, and probably the most important thing you need to know about the internet. DNS allows you to find IP addresses by looking them up in a database. DNS is essentially a phone book for computers. If you want to find an IP address, you can look it up in DNS.
There are several different types of DNS servers, but all of them serve the same purpose: to translate human-readable names into computer-readable addresses. For example, if you wanted to visit “http://www.example.com” on the internet, your browser would ask a DNS server for that IP address. The server would lookup “www.example.com” in its database and give you back an address like “74.125.167.48” that you could use to connect to that website. Without DNS, we would have no way of finding other computers on the internet or connecting to them to exchange information or do business with them.
How does it work?
It works like this: When you type in a URL, DNS sends it on to your web server. If your server doesn't exist, DNS returns an error message instead of sending the request on to the next website in line. If your server does exist, it checks its cache to see if a page with that URL already exists. If so, it sends the request on to the next website in line without creating a new copy of that page in its own cache or sending any data back to the original requestor (the user).
This process is called caching. The other website may have changed its content since then, so DNS updates that information in its own cache as well (called recaching). The request ends when DNS sends the user's request on to the final destination website. In this way, DNS is an essential tool for ensuring that each website you visit gets routed to the correct one, based both on domain names and IP addresses.
