E-commerce or electronic commerce refers to the buy-and-sell of products through use of advanced networking technologies like internet. For this to happen, computer scientists and engineers have come up with "enablers" that facilitate online shopping which includes secure payment gateway software, shopping cart software etc. Shopping cart software has become one of the most popular pieces of online store software and forms the backbone of most shopping portals.

Online shopping cart is used to keep track of all items selected by online purchaser and it also displays total amount to be billed on checkout. It is almost similar to the billing software used by supermarkets all over the world. It is designed in such a way that it is analogous to the physical trolleys we use in supermarkets.

online shopping cart icon is shown at the bottom of each product image, generally below the marked price in the web page. The shopper goes through the product listings and product descriptions in the online shopping portal and if he decides to purchase a particular item on sale, he/she will mark that item and drag or select that item using the online shopping cart icon.

The shopping cart panel displays item selected by the online purchaser , its product code, its price, discount etc. If the customer wants to buy some other products as well he can browse through product listings and add the items he wishes to his shopping cart in addition to the item he has already selected.

The application may looks simple and easy to build. But developing such software demands high technical expertise in various areas such as real time database management, accounts and billing, secure payment gateway etc. It is also important that the team which develops this software does a thorough analysis of the expected customer profile and uses this knowledge to develop "usability" in the software.

Concept of cookies in Hypertext Markup Languages (HTML) is utilized fully in developing the shopping cart software. Two types of such software are available in the market today. The first type requires a one time payment and unlimited usage on purchase and the second type requires monthly or annual subscription charges for its hosted services.