An online shopping cart is a software package that creates a Web page that displays the items that the customer has chosen for purchase while shopping on your Web store. The cart displays the price, extended price, and possibly shipping and handling costs. Customers can change item qualities, and possibly shipping and handling costs. Customers can change item qualities, delete items, or advance to payment data page.
When the customer clicks on the Buy button, the cart sends the data to the PayPal Payflow gateway. PayPal strongly recommends that you use a packaged shopping cart product because most merchants find this to be the most cost-effective solution.