There’s no need to confuse things with metaphors as anyone with elementary understanding of maths should be able to understand it:

A cryptographic hash function is an algorithm that:

Given an input, it returns a very large number.

Given a bit-for-bit identical input it returns exactly the same number.

If the input changes by one bit, it _should_ give an extremely different number, so different that it appears to be random.

The probability of two different inputs producing the same output is extremely low, and the better the hash function, the lower this probability is.