How does Handshake work?

Could you please elaborate on the mechanics of Handshake? I'm particularly interested in understanding how it functions as a decentralized naming system and how it differs from traditional DNS systems. Additionally, I'd like to know about the role of HNS tokens in the ecosystem and how they contribute to the security and decentralization of the network. Lastly, could you provide an overview of the consensus mechanism employed by Handshake and how it ensures the integrity of the network?