EOS tokens are ERC-20 compatible tokens distributed on the Ethereum blockchain pursuant to a related ERC-20 smart contract.
EOS.IO is software that introduces a blockchain architecture designed to enable vertical and horizontal scaling of decentralized applications. This is achieved through an operating system-like construct upon which applications can be built. The software provides accounts, authentication, databases, asynchronous communication and the scheduling of applications across multiple CPU cores and/or clusters. The resulting technology is a blockchain architecture that has the potential to scale to millions of transactions per second, eliminates user fees and allows for quick and easy deployment of decentralized applications.
Read more about EOS from at eos.io.