Domain Name System (DNS) is a system used to translate human-readable domain names, such as www.example.com, into IP addresses, which are used to locate web servers and other network devices on the internet. DNS works by mapping domain names to IP addresses using a hierarchical system of domain name servers, which are distributed across the internet. DNS can be used to manage domain names, configure email and web hosting services, and implement security measures, such as DNSSEC. DNS can also be used to redirect traffic, block access to certain domains, and perform other advanced functions.