What is the function of a Domain Name System (DNS)?

The Domain Name System (DNS) translates human-friendly domain names into numerical IP addresses that computers use to communicate.

The Domain Name System, often referred to as the 'phonebook of the internet', is a hierarchical and decentralised naming system for computers, services, or any resource connected to the internet or a private network. It associates various information with domain names assigned to each of the participating entities. The most prominent function of DNS is to translate domain names, which are easy for people to remember, into numerical IP addresses, which are required for locating and identifying computer services and devices.

When you type a URL into your web browser, your computer doesn't automatically know where that website is located. It needs to find out the IP address of the website so it can send a request to the right place. This is where DNS comes in. Your computer sends a query to a DNS server, asking for the IP address associated with the domain name. The DNS server then responds with the correct IP address, and your computer sends its request there.

DNS is a distributed database implemented in a hierarchy of DNS servers. This hierarchy starts from the 'root' servers, whose information is hardcoded into your system. If the root server doesn't know the answer, it will direct the query down the hierarchy. This process continues until the query finds a server that knows the correct IP address and can respond with it.

The DNS system is crucial for the functioning of the internet. Without it, we would have to remember the IP addresses of every website we wanted to visit, which would be incredibly difficult and impractical. By translating domain names into IP addresses, DNS makes the internet much more user-friendly and enables us to navigate the web with ease.