I've been long muddled by the meanings of "hash", "hash function", "hash value", "message digest", and "hash table" in Compute Science.

Now finally I've made it clear to me that a hash function is simply a one-way encryption function which often is used to ensure a data file, or packet, transmitted over the internet has not been garbled.

Brouhaha. All that hodgepodge of different names and terms.

It's the same old hash of hash function over and over again, all in all.

By the way, a function is not a mapping.