Often you will have a product available in more than one version. What about a black or white iPad? Or the download, DVD or Blu-ray version of VirtueMart the Movie. Of course it would be easy to implement a new product for each version, but that is not always what you want. If it makes sense in your version dilemma to have the versions selectable on one product page, then this is the recipe for you. And VirtueMart will handle the stock control for each version separately.
Write down the different versions you will create and make a note of the products you intend to apply them to. Fire up VirtueMart and read on.