SHA-256, which stands for Secure Hash Algorithm 256-bit, is a cryptographic hash function that produces a 256-bit long hash value. It takes an input of any size and generates a fixed-size string of numbers and letters, typically represented in hexadecimal.This function is widely used for securing transactions and data integrity. In the mining process, for example, miners use SHA-256 to solve complex mathematical puzzles. This ensures that transactions added to the blockchain are valid and secure.The unique aspect of SHA-256 is that even a small change in the input will produce a significantly different hash output. This makes it extremely difficult to reverse-engineer the original input from the hash, providing a high level of security.Overall, SHA-256 is vital for ensuring security, integrity, and trust in any system that requires verification of data authenticity, especially in decentralized networks. Its robustness is a key reason for its adoption in various applications beyond cryptocurrencies as well.