Unlike restricted proof-of-work (PoW) blockchains like Bitcoin, the Polkadot blockchain allows cross-blockchain transfers of any asset or data, facilitates more transactions per second and needs less infrastructure.
Polkadot uses a nominated proof-of-stake (NPoS) blockchain centered on interoperability of parachains that connect to and are secured by the Relay Chain. Validators can validate both the Relay Chain and the parachains, making it a flexible and scalable blockchain solution.