Okay, I can&#x27;t explain it like you&#x27;re 5...  But here&#x27;s as close as I can get.<p>You&#x27;ve got DNA.  Everyone&#x27;s DNA is unique (shhh, just go with me for a minute).  In fact, let&#x27;s say that we found about 140 GATC pairs, which were also unique (we don&#x27;t need your whole sequence, just those 140 pairs).  Meaning, if we take your 140 GATC pairs, and we take my 140 GATC pairs, we&#x27;d be guaranteed to get different results.<p>Now, if I want to refer uniquely to a person, I can just use those 140 GATC pairs, which looks roughly like QmXGTaGWTT1uUtfSb2sBAvArMEVLK4rQEcQg5bv7wwdzwU (when expressed with upper + lower + numbers).<p>But, you&#x27;ve been thinking to yourself, WHAT ABOUT TWINS?!?<p>Well, great question...<p>...but the cryptographic hash that we use is one where twins are EXCEEDINGLY UNLIKELY.  Like, amazingly, shockingly, oh my god, unlikely.  They exist, but in practice they&#x27;re so uncommon that it doesn&#x27;t matter.<p>Maybe sometime, some unfortunate guy is going to request a picture of Natalie Portman, and get an MP3 of Ted Nugent.  It could happen.  It&#x27;s just super unlikely to ever happen in practice.<p>So, there you have it - a cryptographic hash is... excuse me, because this is a supremely flawed analogy...  kind of like the DNA of a file.