Confirmations refer to the number of blocks that have been added to the blockchain since a specific transaction was included. Each new block represents an additional confirmation for the transactions included in previous blocks.
For instance, if a transaction was included in block 100, and the current block height is 105, that transaction has 5 confirmations.
Each block in a blockchain includes a set of transactions. Miners add new blocks on top of the existing ones, and each new block confirms the transactions in the previous blocks. The more confirmations a transaction has, the more secure it is considered to be.
While it's possible for a block to be orphaned due to network forks, a transaction with more than 3 confirmations is generally considered very secure under normal network conditions.
If a Bitcoin transaction is included in block 100, and the current block height is 103, the transaction has 3 confirmations and is considered secure. If the block height increases to 104, the transaction has 4 confirmations and is even more secure.
Different cryptocurrencies may require different numbers of confirmations to be considered secure. This is due to variations in network hash power and implementation details. Wallets and services will often specify a required number of confirmations before they consider a transaction to be valid.
Each additional confirmation adds another level of security to a transaction. It's important to use an appropriate number of confirmations depending on the specific blockchain and the value of the transaction.
For instance, a Bitcoin transaction might be considered secure after 6 confirmations, while a Litecoin transaction might require 12 confirmations due to its faster block time.
* All terms and definitions may update as the Cryptionary improves.