(
Unspent
Transaction
Output) The Bitcoin accounting system that keeps track of the user's available coin balance. Also known as an "address-based" model, the UTXO system is very different from the common accounting method in which a running balance is maintained. The user's UTXO balance is computed in real time from numerous UTXO records (like having cash in several rooms throughout the house). All UTXOs are maintained in the UTXO database (UTXO set). In contrast, Ethereum uses the traditional accounting method. See
Ethereum account model. For more on UTXO, see
Bitcoin transaction.