Bitcoin, Litecoin and Dogecoin Track Spendable Funds as Outputs

Bitcoin (BTC), Litecoin (LTC) and Dogecoin (DOGE) track spendable value as separate transaction outputs, a design that explains why a wallet can display one balance while a payment creates change.

Zcash (ZEC) follows that model for transparent funds, but holds shielded funds in notes. The distinction matters when comparing the networks: the same accounting label does not describe every type of Zcash transaction.

Bitcoin paper author Satoshi Nakamoto outlined transactions that draw on previous payments and produce new outputs. He announced the paper on Oct. 31, 2008. The paper described the mechanics without using the term unspent transaction output, or UTXO.

A Bitcoin wallet calculates its balance by totaling the spendable outputs controlled by its keys. A transfer can consume more than one output and create new ones, including an output for the recipient and another returning unused value to the sender. The displayed balance represents those spendable pieces together.

An output remains available until a valid transaction spends it. Nodes check whether a proposed payment tries to reuse an output already consumed in the accepted chain. Bitcoin’s defense against double spending also depends on transaction validation and the proof-of-work chain that establishes its transaction history.

Litecoin uses UTXOs on its main chain and offers an optional MWEB privacy layer. Dogecoin Core also constructs payments from unspent outputs. Those features sit alongside the shared method of tracking funds available to spend.

Zcash separates transparent funds, which use UTXOs, from shielded funds, which use notes. Describing the whole network as UTXO based would leave out how its shielded funds are represented.

Ethereum provides a different comparison. It records Ether (ETH) balances in account state rather than assembling a wallet balance from individual spendable outputs. That difference helps explain why a Bitcoin payment may return change even when the sender’s wallet shows a single balance.

Transaction structure alone does not prevent double spending. It also does not make Bitcoin payments anonymous: Bitcoin’s transaction history is public, even when users move funds through fresh addresses.