Source. Crypto info.com
What is Qtum?
Qtum combines Ethereum's revolutionary Smart Contract ability with Bitcoin's impressive security to create a coin that is suitable for adoption by large organizations and individuals alike. The founders state Qtum is the first 'UTXO-based smart contract system with a proof-of-stake (PoS) consensus model.'
Ethereum's ability to run Smart Contracts on the blockchain can revolutionise entire industries, but they can be vulnerable to hacking if not coded correctly. Bitcoin has been battle tested for a decade and runs on secure code but cannot run Smart Contracts. So Qtum combines the best of the two, using Bitcoin core code that runs on a machine running an Ethereum Virtual Machine.
Qtum accomplishes communication between the two layers of software by using an Account Abstraction Layer (AAL) that hides the identities of each transacting party.