Hash Function

A hash function is a kind of cryptographic function which, given an arbitrary amounts of bits as input, outputs a fixed amount of bits. Hash functions are one-way functions, this means that it is computationally easy to obtain the output given the input, but it is infeasible to obtain the input given the output. Hash functions are also designed in such a way that even if only 1 bit of the input is modified, the output changes completely and is totally unrelated to the previous one.

Cryptocurrencies make wide use of hash function and they are at the core of network security

Sources:

https://fintechmagazine.com/financial-services-finserv/140-blockchain-and-crypto-words-ultimate-z-glossary