Polkadot is a blockchain network designed to support various interconnected, application-specific sub-chains called parachains (short for parallelized chains). Each chain built within Polkadot uses Parity Technologies' Substrate modular framework, which allows developers to select specific components that suit their application-specific chain best. Polkadot refers to the entire ecosystem of parachains that plug into a single base platform known as the Relay Chain. This base platform, which also leverages Substrate, does not support application functionality but instead provides security to the network's parachains and contains Polkadot's consensus, finality, and voting logic.