What is Hashing

https://crypto.stackexchange.com/questions/6784/what-is-the-difference-between-a-hash-and-a-permutation?newreg=12ddb39ee2ec4b4ba5d00996bd2b7093

As defined by Wikipedia a hash function is

[…] any algorithm or subroutine that maps large data sets of variable length to smaller data sets of a fixed length. For example, a person’s name, having a variable length, could be hashed to a single integer. The values returned by a hash function are called hash values, hash codes, hash sums, checksums or simply hashes.

and when you search for a permutation you find:

In mathematics, the notion of permutation is used with several slightly different meanings, all related to the act of permuting (rearranging) objects or values. Informally, a permutation of a set of objects is an arrangement of those objects into a particular order.