SHA-256 is a successor cryptographic hash function to SHA-1, which provides more secure and reliable communication between internet applications.

SHA-256 stands for Secure Hash Algorithm, where the number represents the length of the hash. SHA-256 outputs a 256-bit hash, and there are six other variants of the SHA algorithm which differ with output, size, and rounds. SHA-256 was released to address the security vulnerabilities discovered in the deprecated SHA-2 algorithm.