Shopping cart is an application used in e-commerce to enable people making purchases online.
The software allows online shopping customers to accumulate a list of items for purchase. Upon checkout, the software typically calculates a total for the order, including shipping and handling (i.e. postage and packing) charges and the associated taxes, as applicable.
Licensed software: The software is downloaded and then installed on a Web server. This is most often associated with a one-time fee, although there are many free products available as well. The main advantages of this option are that the merchant owns a license and therefore can host it on any Web server that meets the server requirements, and that the source code can often be accessed and edited to customize the application.
Hosted service: The software is never downloaded, but rather is provided by a hosted service provider and is generally paid for on a monthly/annual basis; also known as the application service provider (ASP) software model. Some of these services also charge a percentage of sales in addition to the monthly fee.
This model often has predefined templates that a user can choose from to customize their look and feel. Predefined templates limit how much users can modify or customize the software with the advantage of having the vendor continuously keep the software up to date for security patches as well as adding new features.