Q&A: What is the relationship between UTXOs and transactions in Bitcoin Cash?

• UTXOs and Transactions in Bitcoin Cash
  • A transaction is the machine that consumes and creates UTXOs
  • Key implications
  • Common transaction shapes

Question:

What is the relationship between UTXOs and transactions in Bitcoin Cash?

Answer:

I have what I need from the wiki. Here’s the answer:

§UTXOs and Transactions in Bitcoin Cash

Bitcoin Cash has no notion of account balances. Instead, the blockchain is a ledger of transactions, and the actual “money” lives in UTXOs (Unspent Transaction Outputs). The two are two sides of the same coin:

§A transaction is the machine that consumes and creates UTXOs

A BCH transaction has two parts, following a double-entry bookkeeping model (source: transaction-anatomy.md):

• Inputs (debits) — references to outputs of previous transactions that the sender is now spending. Each input points to a specific prior output and includes a signature proving ownership.
• Outputs (credits) — new chunks of value, each locked to a specific address (and amount, in satoshis).

So the relationship is a cycle: outputs created by one transaction become the inputs that another transaction later consumes.

• Inputs destroy old UTXOs.
• Outputs create new UTXOs.

Every output that has not yet been referenced as an input is, by definition, “unspent” — a UTXO (source: utxo.md).

§Key implications

• No balances, only sums. A wallet’s “balance” is just the total of all UTXOs it can spend (source: utxo.md).
• UTXOs are indivisible and must be spent in full. To send 1 BCH from a single 3 BCH UTXO, the transaction creates a 1 BCH output for the recipient and a ~2 BCH change output back to the sender (minus the fee) — typically one input, two outputs.
• Fees are implied. The fee is not a field in the transaction; it’s the difference between the sum of inputs and the sum of outputs, collected by the miner who includes the block (source: transaction-anatomy.md).
• Chain of ownership. Because a child transaction spends a parent transaction’s outputs, transactions form chains (source: transaction-chaining.md). This dependency is exactly what prevents double-spending: once an output is consumed as an input, it can’t be spent again.

§Common transaction shapes

• Simple payment with change: 1 input → 2 outputs (recipient + change)
• Aggregating: many inputs → 1 output
• Distributing: 1 input → many outputs

Sources: PSF LLM Wiki — utxo.md, transaction-anatomy.md, transaction-chaining.md (drawn from Mastering Bitcoin Cash, chapters on transactions).

In short: transactions spend UTXOs and produce new UTXOs. A transaction is a state transition; UTXOs are the state.

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