Blockchain domains are a relatively new and important aspect of the burgeoning Web3.0 community. They are not necessarily a progression of Web2.0 so much as a deviation from the globally deployed domain names system.
Today’s DNS is like a phone book directory that indexes websites and their corresponding IP addresses via a hierarchy called the Domain Name System (DNS). At the top of this hierarchy is the root domain name, or the dot(.), which is managed by the Internet Corporation for Assigned Names and Numbers (ICANN). Registries manage the Top Level Domains that hang of the root (e.g Verisign manage .com) who accredit Registrars to sell and delegate Second Level domain names.
By contrast, blockchain domains rely on a publicly accessible blockchain and are made up of a group of complex smart contracts that make it work. The owner of the domain name has the private key so owns it outright.