What is Confirmation?
A transaction has N confirmations when N blocks have been mined on top of the block that included it. More confirmations exponentially reduce the chance the transaction will be reversed by a reorg. For high-value transfers, six confirmations are a common threshold.
Why Confirmation matters
Understanding Confirmation is part of building a solid mental model of how Bitcoin, blockchain and Web3 systems actually work. Concepts in the Bitcoin category sit at the foundation of the broader stack — get them right and the rest is far easier.
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Related terms
- Reorganization (Reorg) — Replacing recent blocks with a competing chain that has more work.
- Block — A bundle of transactions added to the blockchain.
More bitcoin terms
- Address (Bitcoin / Crypto Address) — A public destination for receiving cryptocurrency.
- Block Header — The metadata at the top of each block.
- Block Reward — New coins paid to the miner of a block.
- Difficulty — A parameter that controls how hard it is to mine a block.
- Double Spend — Attempting to spend the same coin twice.
- Halving — The scheduled 50% cut in Bitcoin's block subsidy.
- Hash Rate — The total computational power securing the network.
- Mining — Producing new blocks by performing Proof of Work.
Keep exploring
Continue with the full blockchain glossary — 136 terms in total — or read the developer blog and FAQ for deeper context.