DNS stands for Domain Name System. It is a complex network but a fundamental part of the Internet infrastructure. DNS can be seen as an online telephone book of the internet, but instead of linking phone numbers to people, DNS links domain names to IP addresses. There is a server behind each website or service, and each server has its own IP address.
IP addresses are the numerical addresses that computers use to communicate with each other on the internet. DNS ensures that you get to the IP address of the server on which the relevant website is located when you type the domain name (the URL of a website) in the browser. The browser sends a request (a DNS query) and is received by a DNS server or DNS resolver. These resolvers are usually operated by an ISP (internet service provider). It translates human-readable domain names into machine-readable IP addresses and will make multiple requests to resolve the desired IP address.
DNS is structured as a hierarchy of different levels called DNS zones. A DNS zone is the entire scope for managing domains and/or subdomains, such as example.com, www.example.com and test.example.com. They enable several benefits and functionalities to different sections of a domain name hierarchy.
A DNS zone is managed by a name server and contains DNS records, a fundamental component that provides specific information and other data per record about a domain or subdomain. Each DNS record serves a specific purpose. When a DNS resolver receives a query for a domain within a specific DNS zone, it consults the corresponding zone file to retrieve the relevant DNS records and provides the requested information.