The Blockchain Name Service is a blockchain that will list all the active blockchains in the world, as well as their respective tokens and their bootstrap nodes. Right now, there is no such blockchain, but with the observed rise in the number of blockchains, the crypto world needs it.
The easiest way to understand the purpose of the Blockchain Name Service, is to make an analogy with the role of the DNS (Domain Name System) on the Internet as we use it today: it lists all domain names and websites and allows anyone to connect to any website by using a simple comprehensive URL, such as www.iov.one, instead of 188.8.131.52. The Blockchain Name Service is like the DNS for Blockchains. It allows anybody to access any token on any blockchain by using a simple, unified and decentralized approach.