In blockchain systems, transaction finality is a critical concept that signifies the certainty that a transaction has been permanently recorded on the blockchain and cannot be reverted. This characteristic of finality varies across different consensus mechanisms. For example, Proof of Work (PoW) networks tend to achieve finality based on the depth of block confirmations, meaning that the deeper a transaction is in the blockchain, the more secure it is from being undone. In contrast, Proof of Stake (PoS) systems may use different methods, such as checkpoints, to confirm finality. Understanding transaction finality is essential for users, as it impacts their confidence in the reliability and security of blockchain transactions.