The Domain Name System (DNS) establishes the mapping between domain names and IP addresses.
TCP/IP uses IP addresses to connect to devices. Users find it is difficult to memorize the IP address of each device. Therefore, the host naming mechanism is specially designed to match IP addresses with host names in the string format. The DNS provides the conversion and query mechanism between IP addresses and host names.
The DNS uses a hierarchical naming mode to specify a meaningful name for each device on a network, set the DNS server, and establish the mapping between the domain name and the IP address.