The DNS (an acronym for Domain Name System) is a server structure that allows a domain name to be associated with its IP address and other key information every time an Internet search is conducted.
The DNS takes care of translating IP addresses, which are numerous and difficult for a human being to memorise, into a meaningful sequence of characters: the domain name.
The DNS, in a nutshell, is a kind of ‘phone book’ for Internet searches: it retrieves the ‘number’ (IP) of a website from its ‘name’ (domain).
In short, when a user (or client), surfing the Internet, types a domain name in the browser‘s search bar, the latter contacts DNS servers to obtain the associated IP address. They are organised in a hierarchical manner, so as to retrieve the requested information in a precise and scalable manner.
First, the search query is forwarded to a root nameserver which, precisely, analyses the root of a domain name, i.e. the ‘first level’ of the DNS structure.
In fact, the request is then forwarded to the TLD nameservers, which are in charge of storing the TLD information.
At this point, the search is taken over by the authoritative nameservers, which store information on the other levels of the domain, subordinate to the first, in order to return the corresponding IP address to the client.
Surfing the net can be risky, but users can protect themselves by using private DNS: unlike traditional public servers, these establish an encrypted connection with the client.
Thanks to Cryptography, it is indeed possible to reduce the risk of being intercepted and consequently diverted to a false IP address, associated with spam or phishing practices.
In recent years, experimentation with DNS systems based on blockchain technologies has also taken off. DNS, in this case, are represented by a suite of smart contracts that regulate and manage the operation of domains; as there are no centralised intermediaries, the information is accessible to all and is immune to censorship.