What is a HNS domain name?

Could you please explain what a HNS domain name is? I'm not familiar with the term and would appreciate a concise yet informative description. Is it a type of domain name specifically used in the cryptocurrency or blockchain industry? If so, how does it differ from traditional domain names, and what are its unique features or benefits? Additionally, how can one acquire or register a HNS domain name, and what are the potential use cases for it?