Transaction
Definition
A transaction is a signed instruction submitted to a blockchain that, once included in a block, changes on-chain state such as balances.
A transaction is the basic unit of activity on a blockchain. To make one, your wallet assembles the details (recipient, amount, any contract call, gas settings, and a nonce) and signs them with your private key. The signed transaction is broadcast to the network, waits in the mempool, and, once a validator includes it in a block, its effect on state (such as moving funds) becomes part of the permanent record.
Why it matters
Every meaningful on-chain action is a transaction: sending tokens, granting a token approval, or calling a smart contract. Each is identified by a unique hash you can track on a block explorer. Because a confirmed transaction generally cannot be reversed, reviewing exactly what you are signing, before you sign, is the single most protective habit in self-custody.
Common misunderstanding
Two ideas mislead newcomers. First, that a transaction can be cancelled after it confirms; in general it cannot, which is why care beforehand matters so much. A pending transaction can sometimes be replaced by resubmitting the same nonce with a higher fee, but a confirmed one is final. Second, that all transactions simply send coins. Many instead authorise a contract to act, and those authorisations, such as approvals and permits, can have lasting effects even when no funds move immediately. For that reason, pausing to read the details of any authorisation, not just transfers, is the habit that prevents most avoidable losses. In self-custody, that moment of review is your last line of defence.
Related terms
Note: CamoCrypt is security & education only — no prices, no predictions, no investment advice. Verify every address and contract yourself; we cannot recover lost funds and neither can anyone who contacts you claiming they can.