Fba is fulfillment by amazon. where you have to get an appointment from amazon warehouse and transfer all your listed inventory there. after that any order arrives amazon pack deliver I mean handle everything. Amazon will fulfill all. MFN is merchant fulfillment where you have to pack and deliver it to customer and handle returns also. if you choose easyship then you will pack the product easyship will collect it from your address and deliver it to customer. same return also.