What is Change output?
The output that returns leftover value to the sender when a spent UTXO is larger than the amount being sent.
Because UTXOs are consumed whole, sending 0.1 BTC from a 0.5 BTC UTXO produces two outputs: 0.1 to the recipient and roughly 0.4 back to a change address you control.
Wallets normally use a fresh address for change, which is good privacy practice but confuses newcomers reading their own transactions in a block explorer.
Related terms
UTXO
An unspent transaction output: a discrete chunk of bitcoin locked to a condition. Bitcoin has no account…
Wie es funktioniertTransaction
A signed instruction consuming one or more UTXOs and creating new ones. Once confirmed it cannot be reversed.
Keys & custodyAddress
A string encoding the conditions under which an output can be spent. Bitcoin's equivalent of an account…
This definition is part of the Bitcoin Logical glossary. For the fuller explanation, start with Lernen, or see the live numbers on Das Bitcoin-Signal.