what is hash functionality
A hash function is any function that can be used to map data of arbitrary size to data of fixed size.The values returned by a hash function are called hash values, hash codes, hash sums, or simply hashes. One use is a data structure called a hash table, widely used in computer software for rapid data lookup.Hash functions accelerate table or database lookup by detecting duplicated records in a large file.he values returned by a hash function are called hash values, hash codes, hash sums, or simply hashes. One use is a data structure called a hash table, widely used in computer software for rapid data lookup.