Ask a little kid who thinks he or she knows everything about computers, grab a big mug of tea, and let them tell ya! The word they are trying to say is "hexadecimal", or 16.

You know how they ask for passwords to be at least 8 characters long? Thats along the same lines.

Plus, most computers will ask, in these 8 or more characters, are you going to put something, or will you also include nothing? I think its less work if there is always something - then the computer knows that if there is nothing, its a mistake, or maybe the end of the word (thats WORD, not world!).

There is no end of computer info on the web - what youre asking is kind of like, why is the sky blue? Or maybe why are roads flat and wheels round. Youve really hit at the core of the matter (lol thats a very very old computer terminology joke, core).