All terms
A signed instruction to change the state of the blockchain.
A transaction says what you want to happen: move this token, call this contract, deploy this code. You sign it with your private key, broadcast it to the network, and wait for a validator to include it in a block.
Once included and confirmed, it is permanent. There is no chargeback, no reversal and no dispute process. That finality is a feature and a hazard in equal measure.
Every transaction gets a hash, a unique identifier you can paste into a block explorer to see exactly what happened.
That a transaction can be canceled. Once it is confirmed there is no undo, no chargeback and no arbitration. The only thing you can sometimes do is replace it while it is still pending, by resending with a higher fee.
Common questions
Can a transaction be canceled?
Why is my transaction stuck as pending?
Where this comes up on the site
The guides that actually use this word, rather than a list of everything we have written.
Where to go next
More foundations terms
Want this explained out loud?
Some of these land faster in conversation than in writing. Sessions are one to one and you can ask anything, including the things that feel too obvious to ask.