UTXO
Also · Unspent transaction output · Coin
A UTXO is an unspent transaction output, the unit in which Bitcoin tracks ownership. Spending consumes whole UTXOs and creates new ones, including change.
Bitcoin has no accounts and no balances in the banking sense. It tracks unspent transaction outputs, or UTXOs. Each one is a chunk of bitcoin locked by spending conditions, usually a key. Your “balance” is simply the sum of the UTXOs your keys can unlock.
A UTXO is spent whole. To pay 0.3 BTC from a 1 BTC output, a transaction consumes the full output and creates 2 new ones, the payment and 0.7 BTC of change back to you, minus fees. This model makes verification simple and leaves public traces that chain analysis reads. How you pick and group your UTXOs shapes both your fees and your privacy.
In French · UTXO
