Each machine connected to the internet (computer or server) has a specific IP address, which corresponds to a specific numerical code. The acronym DNS (Domain Name System) indicates the computer system that deals with "translating" an IP address into a name, in order to make the site easily accessible for all users on the network.
Through the DNS system, the IP addresses, made up of numerical sequences, are "translated" into the domain names that we type in the browser bar when we surf online.