system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How can EVERY snow flake be unique?
gpt
It's more of a statistical thing than an absolute statement.  A snowflake's shape is determined by the quantity of water in it, any impurities in the water, the atmospheric conditions in which it was created including temperature, humidity and atmospheric pressure and so on.  There are so many different variations of those things that the number of potential snowflakes is vastly larger than the number of snowflakes which have ever fallen.

So, there is a very small chance that two snowflakes have been precisely the same.  That chance is close enough to 0 that people act like it's 0 and say that every snowflake is unique.

Fingerprints are similar -- it's conceivable that two people will actually have the same fingerprints, but there are so many different things that go into determining our exact fingerprints that we act as if they're all unique.  And, that's borne out in practice -- we have yet to discover two people with identical fingerprints (even identical twins don't have them.)