Hash functions

A hash function is a process that takes input data and transforms it into a fixed-size string of characters, often called a hash or hash value. Think of it like a unique digital fingerprint for the data. Even a small change in the input results in a completely different hash. Hash functions are used in security (to verify data integrity), digital signatures, and storing passwords securely. They are designed to be fast, unique, and irreversible, meaning you can't easily derive the original data from the hash.