AI solution for Interview Question on BFE.dev
21. What is DNS? How does it work?

DNS stands for Domain Name System. It is a system that translates domain names (like www.google.com) into IP addresses (like 172.217.7.206), which are used by computers to identify each other on the internet.

DNS works by using a hierarchical structure of authoritative name servers that store the data for different domain names. When a user types in a domain name, their computer sends a query to a recursive DNS resolver, which checks its cache and then sends a request to a root server. The root server then refers the query to a top-level domain (TLD) server (.com, .org, etc.), which in turn refers the query to an authoritative DNS server for the specific domain.

The authoritative DNS server then responds with the IP address for the requested domain name, which is passed back up the chain to the user's computer. The recursive DNS resolver stores the IP address in its cache, allowing it to respond more quickly to future requests for the same domain name.