What Is e-Commerce?

One of the most commonly required features of a Web site today is an e-commerce component. By allowing users to purchase items online, millions of businesses have been able to expand the scope of their sales from local to global. The online catalog allows users to see what items are offered by the store. Within the store, a user chooses items and puts them in his shopping cart. In this way, users can add or remove items from their shopping carts while they are in the store. The basic components of any e-commerce application are a catalog, which allows the user to see the items offered for sale; a shopping cart, which allows the user to purchase items, and a transaction history, so a user can browse all of his past purchases.

Figure 21.1 shows the flow of an e-commerce application, from browsing through available items to the completion of the purchase.