SHA-3 is a cryptographic hash function designed to provide secure data integrity. It was developed by the National Institute of Standards and Technology (NIST) and finalized in 2015 as part of the Secure Hash Algorithm family. Unlike its predecessors, SHA-3 is based on a different structure called Keccak, which enhances its security and performance. SHA-3 produces a fixed-size output, typically 256 bits, regardless of the input size. It is widely used in various applications, including digital signatures, password hashing, and data verification, ensuring that even a small change in the input results in a significantly different hash output.