Transition to Web3 - Course 1 | Blockchain Basics
A hash is essentially a summary of the original data.
Bitcoin uses SHA (Secure Hash Algorithm)-256 hash. SHA-256 is an algorithm that simply turns any kind of data into a standard-size (256 bits) hash. One input always generates the same hash, but it is impossible to predict the input back from the hash.
š Ā Fun fact: SHA-256 was actually developed by the National Security Agency in the US.