17) Q: Retail? / Release?
Installation using the Apple created DVD of OS X, that either comes with a purchased Mac (iMac, Mac Pro ...) or sold separately. The Advantage of a "Retail" install is that it has no "fixes" or "patches" that are required to be carefully chosen during the installation process. Of course, you can instead apply any needed fixes once the installation has finished, if it is needed, so that your equipment is recognized in OS X.
The downside is the OS X installation DVD will not boot on a non-Apple hardware without a boot loader. You can use chameleon, the media can be a CD or a USB key, on a CD you would swap it for the retail disk at the boot loader's menu
Also known as a Distro, or Distribution, an installation DVD of OS X which has fixes and patches added by a team of programmers to simplify the installation for beginners. In general, a "Release" includes: a bootloader that allows you to launch the installation DVD of OS X on non-Apple machines and once first loaded, "customization"options, a menu where you choose patches such as modified .kext to be applied depending on your hardware. Among the most popular, I would mention that JaS, Kalyway, iATKOS.
The biggest difference between Retail and Release is the ability to update the Retail version without risk of conflicts that may be encountered with various Release fixes/patches. In general, Retail installation requires a degree of skill slightly higher, as beginners may find a Release instal less difficult, but potential problems can be harder to diagnose as unlike Retail, you don't have direct knowledge of everything that may have been added.