I hope this is the right place for this question .. sometimes thats the hardest part of making a post, lol

Anyways, in the simplest terms possible can someone explain Hard coding to me. I understand it is essentially embedding data into the source code of a program, but lets take an example that may help you help me :

If a site admin hardcodes a password into the script of a site why wouldn't the password be in the source code? Can someone explain this to me?