The Domain Name System (DNS) is a hierarchical, decentralized system that is used to map domain names (such as www.example.com) to IP addresses (such as 192.0.2.1). It is the system that translates human-friendly domain names into machine-readable IP addresses, allowing users to access websites, email servers, and other network resources using domain names instead of IP addresses.
Here's an overview of how the DNS works:
A user types a domain name into their browser (e.g. www.example.com) and the browser sends a request for the IP address associated with the domain name to a DNS resolver.
The DNS resolver, which is typically provided by the user's internet service provider (ISP), checks its cache to see if it has the IP address associated with the domain name already stored. If it does, it returns the IP address to the browser.
If the DNS resolver does not have the IP address in its cache, it sends a request to a root DNS server. The root server responds with the IP address of a top-level domain (TLD) DNS server (e.g. .com, .org, etc.) associated with the domain name.
The DNS resolver then sends a request to the TLD DNS server, which responds with the IP address of the authoritative DNS server for the specific domain name.
The DNS resolver receives the IP address from the authoritative DNS server and stores it in its cache.
The DNS resolver returns the IP address to the browser, which then uses it to connect to the web server hosting the domain name.
The DNS is a hierarchical system, so a DNS resolver can ask other DNS servers for the IP address of a domain name if it doesn't have it in its cache. This allows the DNS to scale to handle the millions of
