Polkadot (DOT) is a multi-chain blockchain protocol designed to provide interoperability between different blockchains. Developed in 2016 by Gavin Wood, one of the co-founders of Ethereum, Polkadot allows blockchains to share information and work together. Polkadot's main goal is to create a completely decentralized network where users have full control over their data and transactions. The network's main token, DOT, is used to govern, stake, and link parachains to the Polkadot mainnet, ensuring the security and stability of the entire ecosystem.