How does ens work?

Could you elaborate on how ENS functions? I'm curious about the technicalities behind it. What kind of technology does it utilize to enable the mapping of human-readable names to machine-readable addresses? Is it based on blockchain? And how does it ensure the uniqueness and security of these names? Also, how does it handle the registration and resolution process? It would be great if you could provide a high-level overview of its working mechanism.