Starknet functions as a Validity-Rollup (or ZK-Rollup) Layer 2 solution atop Ethereum, designed to significantly scale decentralized applications without sacrificing security.
It accomplishes scaling by aggregating transactions into a single STARK proof computed off-chain. This proof is subsequently committed to Ethereum in a singular transaction, achieving markedly increased throughput, quicker processing speeds, and reduced expenses, while maintaining the strong security backbone provided by Ethereum's settlement layer.
STRK serves as Starknet's native cryptocurrency.