A domain name is a human-readable string used to identify a specific IP resource on the Internet. It functions as an alias for complex numeric IP addresses, enabling users to access websites and services without memorizing binary or hexadecimal sequences. Domain management is governed by ICANN and executed through a network of registrars.
How it works
The resolution process translates a domain like www.example.com into an IP address via the DNS hierarchy. When a request is made, the resolver queries root servers, TLD servers, and finally authoritative nameservers. This hierarchical lookup ensures that changes to a server's IP address do not require changing the domain name itself.
- Root Zone: The starting point of the DNS hierarchy.
- TLD: Categories like .net, .edu, or country codes like .uk.
- FQDN: A Fully Qualified Domain Name that specifies the exact location in the DNS tree.
Technical specifications are defined in RFC 1035. A domain name can consist of up to 127 levels, though most practical implementations use 2 or 3. The total length cannot exceed 253 characters. For security, DNSSEC (Domain Name System Security Extensions) is often used to provide authentication and integrity of the DNS data.