SHA-256

SHA-256 is a widely used cryptographic hash function that belongs to the Secure Hash Algorithm (SHA) family. It takes any input data and produces a unique, fixed-size 256-bit output. The same input will always generate the same hash, but even the smallest change in input will create a drastically different hash. It’s not possible to reverse-engineer the original input or predict the output in advance. SHA-256 is a core component of the Bitcoin system, where it secures transaction IDs, block hashes, wallet addresses, and constructs Merkle trees. In some situations, such as when computing transaction IDs, SHA-256 is applied twice for added security.