A hash is a cryptographic term that refers to data obtained by passing the initial information through a hash function. In addition, this result may also be called a hash value, a hash code, or a digest.
Hash functions themselves are defined mathematical algorithms that convert any information into a hash of a fixed size (length). Most often, combinations of sixteen characters are used, in which digits from 0 to 9 and letters from A to F are used. The alphabet used, of course, is exclusively Latin.
What is a Bitcoin Hash?
As a simple example, let’s consider the SHA-256 hash function used in Bitcoin - the most common cryptocurrency in the world at the moment. If you skip the sentence through it: "learning to understand cryptocurrency", we get the following result:
fcad2f9fa968636b359f777e5afef3d9e641748e70c8269acf7d2f2217b7a708
What is important - it does not matter how many times we will skip this phrase, on any machine we will do it. The same source information always gives the same hash.
However, if we change at least one letter, for example, start the sentence with a capital letter, or replace one alphabet “e” with the corresponding cyryllic letter, we will get completely different results:
307a2bdf34a3e5058512d14f72f9181edb6d8f7974a4984e7f63a4bca451d2be
and
25a90b9fab31b48bcd252a508341447d7bdec0bff7973e6a84b78672b984bd51
accordingly.
It can be argued that knowing the hash is extremely useful for verifying the accuracy of information without revealing its contents. That is why these algorithms are used for searching closed databases, analyzing large files and providing additional information protection.
In addition, it is the hash function that underlies the operation of most blockchain networks. It is she who is responsible both for coding the already existing information and for the mining process.