DNSSystemen

DNSSystemen, also known as Domain Name System (DNS), is a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates easily memorized domain names to the numerical IP addresses needed for the purpose of locating and addressing services and devices with the underlying network protocols. By providing a worldwide, distributed directory service, the Domain Name System has been an essential component of the functionality of most Internet services since 1985.

The DNS is based on a distributed database implemented in a hierarchy of name servers. The most common records stored in the DNS are the Address (A) record, which maps a domain name to an IPv4 address, and the IPv6 Address (AAAA) record, which maps a domain name to an IPv6 address. Other types of records include the Mail Exchange (MX) record, which specifies the mail servers responsible for receiving email on behalf of a domain, and the Canonical Name (CNAME) record, which maps an alias name to the true or canonical domain name.

The DNS operates using a client-server model. When a user types a domain name into a web browser, the browser sends a DNS query to a DNS resolver, which is typically provided by the user's Internet Service Provider (ISP). The resolver then queries the DNS hierarchy, starting with the root name servers, to find the authoritative name servers for the domain. The authoritative name servers provide the resolver with the requested information, which is then returned to the user's browser. The browser can then use this information to establish a connection to the desired website or service.

The DNS is a critical component of the Internet's infrastructure, enabling the use of human-readable domain names instead of numerical IP addresses. It is maintained by a global community of network operators, domain name registrars, and other interested parties, who work together to ensure the continued operation and security of the system.