Bitcoin transactions cannot be reversed or canceled once they have been confirmed on the blockchain. This is due to the decentralized nature of cryptocurrency, which relies on a network of computers (nodes) to validate and record transactions. Once a transaction is included in a block and added to the blockchain, it becomes virtually impossible to alter or delete. This immutability is one of the key features of Bitcoin that provides security and trust in its system. However, there are instances where users may mistakenly send funds to an incorrect address or fall victim to scams. In such cases, while the transaction cannot be reversed directly, individuals can attempt to recover their funds by reaching out to exchanges or law enforcement agencies for assistance. It is important for users to exercise caution when sending Bitcoin and double-check all transaction details before confirming them, as there is no central authority or customer support available for reversing transactions in cryptocurrencies like Bitcoin.