The basic idea behind an online drop shipping business is that, as a small business owner, you don’t have to maintain a large inventory (or any inventory whatsoever) of products or handle any delivery to your customers. That eliminates the financial cost and risk of having a warehouse full of stuff you might not sell, and the hassle of arranging to send orders all over the country or the world. In fact, you don't have to manufacture or store any products at all.
The internet changes so fast that one year online equals about five years in the real world. But the principles of how to start and grow a successful online business haven't changed at all. If you're just starting a small business online, stick to this sequence. If you've been online awhile, do a quick review and see if there's a step you're neglecting, or never got around to doing in the first place. You can't go wrong with the basics.