In the context of blockchain technology, immutability is a key feature that ensures the integrity and permanence of data. When a transaction is confirmed and added to the blockchain, it cannot be altered or deleted. This characteristic is achieved through cryptographic hashing and consensus mechanisms, making it extremely difficult for any party to manipulate the data without the consensus of the network. Immutability enhances the trustworthiness of digital records, especially in applications such as financial transactions, property titles, and identity management.