In crypto transactions, change is the leftover value returned to the sender when the coins being spent are worth more than the payment plus the network fee. It arises on blockchains such as Bitcoin that use unspent transaction outputs (UTXOs), where each output must be spent in full, much like a banknote. If a wallet holds a single 1 BTC output and the owner pays 0.3 BTC, the transaction creates one output of 0.3 BTC for the recipient and another of roughly 0.7 BTC, minus the fee, back to the owner. Wallets usually send this change to a fresh change address to improve privacy. Account-based chains such as Ethereum deduct the amount from a balance and have no change. Also see Bitcoin (BTC) and Crypto Wallet.