<?php

// you get this from the login creation form
$mypass = "godftw";
$encryptedpass = md5($mypass);

// store $encryptedpass in the database




**


so mr herp derp comes to login

$username = "herpderp";
$mypass = "godftw";

// "ok lets check if its right"

$encrpyt = md5($mypass);

// run query, where pass = encrpyt and username = herpderp
// if the $mypass was different, the encrpytion is difference, so it will fail

?>