Too Long; Didn't Read
Hash functions take an arbitrarily long text as input and then create an output with a defined size. These are known as cryptographic hash functions and are used for connecting the so known blocks in a chain very importantly in a tamper-proof manner. The size of the output of these hash functions will be 256 bits in length. The output of a hash function should make predicting its input value challenging. It is incredibly popular for solving what is known as a mining puzzle in one of the blockchains, such as bitcoin.