Qtum (pronounced Quantum) is a blockchain platform that combines the smart contract functionality of Ethereum with the stability and security of Bitcoin's UTXO (Unspent Transaction Output) model. Developed by the Qtum Foundation, this open-source project aims to bridge the gap between Bitcoin and Ethereum communities, businesses, and technologies, fostering a new ecosystem that can support practical business applications. Qtum introduced the proof-of-stake (PoS) consensus mechanism to enhance scalability and reduce the environmental footprint associated with Proof-of-Work (PoW) systems. Its potential to support mobile applications and lite wallets through Simple Payment Verification (SPV) makes it distinct and versatile.