Debian 7.7.0 amd64 3 DVD Pack is an update package of Debian 7 Wheezy.This update mainly adds corrections for security problems to the stable release, along with a few adjustments for serious problems. Security advisories were already published separately and are referenced where available. Please note that this update does not constitute a new version of Debian 7 but only updates some of the packages included. There is no need to throw away old "wheezy" CDs or DVDs but only to update via an up-to-date Debian mirror after an installation, to cause any out of date packages to be updated. Those who frequently install updates from security.debian.org won't have to update many packages and most updates from security.debian.org are included in this update.
About Debian
The Debian Project is an association of individuals who have made common cause to create a free operating system. This operating system is called Debian GNU/Linux, or simply Debian for short. Debian systems currently use the Linux kernel. Linux is a completely free piece of software started by Linus Torvalds and supported by thousands of programmers worldwide. Of course, the thing that people want is application software: programs to help them get what they want to do done, from editing documents to running a business to playing games to writing more software. Debian comes with over 20,000 packages (precompiled software that is bundled up in a nice format for easy installation on your machine) - all of it free. It's a bit like a tower. At the base is the kernel. On top of that are all the basic tools. Next is all the software that you run on the computer. At the top of the tower is Debian -- carefully organizing and fitting everything so it all works together.