iTunes updates and iPod Updater

Apple released today iTunes update 6.0.5 and iPod updater 2006-06-28, both have whopping 41.8MB and 18.9MB respectively. I've noticed that just this week, Apple has released a couple of updates both for OS X and for Quicktime. Man those downloads where big, I wonder if these were "updates" or re-download of the softwares themselves.