My head is spinning.  Really. 

According to this article by Paul Thurrot, “Microsoft is creating seven versions of Vista for end users (nine if you count the N Editions that will target European markets). To differentiate these products, the company is carefully matching feature sets to the expected markets that will adopt each product version.
  
Two low-end versions of the product, Vista Starter Edition and Vista Home Basic Edition, won’t feature the much-vaunted Aero UI that will adorn all the other Vista versions. Instead, these versions will use a lower-quality, XP-like UI that’s more appropriate for the low-end hardware that infrequent PC users and emerging markets might use. Vista Starter and Vista Home Basic will also lack the rolodex, tab previews, and task bar preview features that other Vista editions will offer.”

Alex Eckelberry