Founded by Ethereum cofounder Gavin Wood, Polkadot is a sharded multichain protocol that enables heterogeneous blockchains to communicate with each other.
Polkadot achieves this with four main components: interoperable chains called relay chains, sharded chains called parachains, parathreads, and bridges to external blockchains. This modular architecture enables Polkadot to scale more effectively than other Layer-1 blockchains as independent networks transmit information between each other.
Developers can experiment with Polkadot using its sister network, Kusama. Projects can then bid for a parachain slot. In contrast to traditional blockchain networks where blocks are processed sequentially, Polkadot's parachains enable parallel execution of blocks, reducing network congestion.
Polkadot's native token, DOT, is used to bid for parachain slots to incentivize participation in its nominated proof-of-stake consensus mechanism as a governance token and medium of exchange.