A Bitcoin transaction confirmation is the process by which a Bitcoin transaction is verified and approved by the Bitcoin network. When a user sends a transaction, it is broadcast to the network, where it is then picked up by miners. Miners use specialized software to solve complex mathematical equations that are generated from the transaction, and then confirm its accuracy.

Once the transaction is confirmed, it is added to the public ledger of all Bitcoin transactions, known as the blockchain. Each block in the blockchain contains a list of transactions, and each new block is added to the end of the chain. Each block is permanently time-stamped and linked to the block before it. This process of linking blocks together forms a chain, which provides a secure way to store transactions and ensure that they cannot be changed.

Once a transaction is included in a block, it is considered to be confirmed. As more blocks are added to the chain, the transaction becomes more and more secure, as it becomes more difficult to tamper with or reverse the transaction. The more blocks that are added, the harder it is to reverse the transaction. Generally, six confirmations are considered to be secure and is the standard for most Bitcoin exchanges.