Polkadot is both a token and a decentralized protocol that can be bought and sold on exchanges like Coinbase or Binance. The Polkadot protocol allows unrelated blockchains to securely communicate with one another,  for example, enabling value or data to flow between Ethereum and Bitcoin blockchains without the need for an intermediary.  It's also intended to be fast and scalable, thanks to the use of numerous parallel blockchains offloading processing demands.