I was wondering about the difference between these two terms... What is the difference between a digest and a hash function?
The basic difference between a hash function and digest is that digest is the value obtained from a hash function.
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, digests, or simply hashes.
One use is a data structure called a hash function, widely used in computer software for rapid data lookup. For example, suppose that you want to count the number of occurrences of the alphabets in a string.
Always remember that the hash digest returns an alphanumeric message which is the digest. Also,the hash function tries to map large data of variable length to a fixed length data.
The terminology is used a little loosely, but I would characterize a "digest" as intended to be unique, so that if any pair of documents produce the same digest, they are almost certainly identical. Hash functions are only intended to split the input into a set of equivalence classes, where most but not all pairs of documents will have different hashes.