an algorithm used to create a unique string for every string that is passed to it
A number of fixed length generated from data of arbitrary length with the aid of a hashing algorithm. The number (also called a message digest) has two characteristics: (1) It is unique to the hashed data. Any change in the data, even deleting or altering a single character, results in a different value. (2) The content of the hashed data cannot, for all practical purposes, be deduced from the hash.
A function of a variable string to create a fixed length value representing the original pre-image, also called message digest, fingerprint, message integrity check (MIC).