Polkadot

Polkadot is a multi-chain network built so that separate blockchains can share security and pass messages to one another. Rather than being a single chain that hosts every application, it acts as a base layer that connects specialized chains, each free to design its own rules, fee model, and governance.

The project was outlined in a 2016 whitepaper by Gavin Wood, a co-founder of Ethereum, and the network launched in 2020. Its development is closely tied to Substrate, a framework that lets teams build a purpose-specific blockchain and then plug it into the wider network rather than starting from scratch.

Architecture

At the center is a relay chain that finalizes blocks and provides shared security. Connected chains, historically called parachains, run their own logic while relying on the relay chain's validator set for finality. This pooled security means a small chain does not need to bootstrap its own validator economy. Cross-chain messaging lets these chains move tokens and data between each other without trusting a separate bridge operator.

Consensus and the DOT token

Polkadot uses a nominated proof-of-stake system. Validators produce and finalize blocks, and token holders nominate validators by staking DOT behind them, sharing in rewards and in the risk of penalties for misbehavior. DOT has three main roles: staking to secure the network, voting in on-chain governance, and bonding to obtain blockspace for a connected chain.

The token's maximum supply is listed at 2.1 billion. Polkadot's issuance is inflationary by design, with new DOT distributed to stakers and to the treasury, and governance can adjust economic parameters. The network's governance has moved through several iterations, with later versions putting more decision-making directly in the hands of token holders rather than an elected council.