E-business is a relatively new concept of using the internet to buy and sell products. The Internet has been around for a long time and people have been shopping on it for a decade. E-business in this context is referring to online business models where the Retailer does not keep an inventory of products, nor do they deal with shipping it to the end customer.
Dropshipping is a retail fulfillment method in which the retailer operates without maintaining any inventory, handling product or shipping. Instead, when a product is ordered by a customer, it is purchased by the retailer, then it gets shipped to the customer. Essentially, the retailer works as a middleman.