What Is a UTXO and How Does It Relate to Transaction Verification?

UTXO stands for Unspent Transaction Output, which is a fundamental concept in the Bitcoin model. A UTXO is the remaining cryptocurrency output from a transaction that can be used as an input for a new transaction.

When a user sends funds, they consume one or more UTXOs as inputs, and the transaction generates new UTXOs for the recipient and for the sender as change. Transaction verification ensures that the inputs (UTXOs) are valid, unspent, and that the sum of the inputs is greater than or equal to the sum of the outputs.

What Is the Purpose of the “Change Output” in a Standard Bitcoin Transaction?
What Is the Role of the UTXO Model in Preventing Double-Spending?
What Is the Role of UTXOs (Unspent Transaction Outputs) in the SegWit Transaction Model?
How Does Transaction Finality Differ across Various Consensus Mechanisms?
How Does the Size of the Hash Output (E.g. SHA-256) Relate to the Nonce?
What Is a Change Address and Why Is It Used in Bitcoin Transactions?
In Options Trading, What Is a Concept Analogous to an “Unspent” Financial Position?
How Does the UTXO Model Differ Fundamentally from the Account/Balance Model Used by Ethereum?

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