The center of an e-commerce online store is the shopping cart. Shopping basket, online shopping cart, web store, e catalog and shopping carts are appropriate metaphors of the familiar trolley used in supermarkets. People go to supermarkets, push shopping carts through the aisles, pick and choose the items needed. They add and remove items from the carts without much effort or thought. Shopping cart software is an effort to translate the ease and control over purchasing in the real world (to which people are so accustomed), to the electronic world of online shopping. It is essentially an extension of a simple order form. A simple order form is generally limited in the amount of interactivity it gives to the customer, and allows a limited number of products and options.
There are several different types of e-commerce online shopping cart available, each with their own advantages and disadvantages:

ASP Shopping Cart Software

(ASP) stands for active server pages the language was written by Microsoft and provides a robust e-commerce platform. ASP Shopping Carts are easy to build edit and manage. The MonsterCommerce shopping cart software is written in ASP and provides an easy to use "back-office" to manage all components of your e-business.

• CGI Shopping Cart:

  The major advantage is that they are supported by all of the major browsers. The disadvantage is they can be hard to set-up and maintain, can be slow, and waste bandwidth and system resources.

• Cookie Shopping Cart:

  These types of e-commerce carts are easy to setup and maintain. They are faster than traditional CGI shopping cart and use less bandwidth and system resources. The disadvantage is they are not supported by browsers that do not support cookies, and become ineffective in cases where the user chooses to turn off cookies in their browsers.

• Java Shopping Cart:

  The advantages are that they can have a content rich and visually pleasing interface (and not limited by HTML). The limitations of this shopping cart software are that since you have to build your store inside the applet, they are hard to customize and can be slow.

• JavaScript Shopping Cart:

  The advantages are that they are fast, easy to set-up and maintain, easy to customize, save bandwidth, and save system resources. The disadvantage is they are not supported by browsers that do not support cookies and JavaScript. Furthermore, it can be difficult to set-up large shopping carts by this approach.

Have time to spare? Visit a web page dedicated to shopping cart abuse.

The question, then, you will have to ask yourself is: do I need shopping cart software tools that come equipped with a turnkey shopping cart? For a small number of products with few options, a full-fledged shopping cart might not be necessary. In such as case, a smaller customized page that accepts credit cards may be sufficient. If you have a large number of products with many variations and options, it may be inconvenient to include them all in a single page. In such a case, it is preferable to display the shopping cart products over a variety of pages, which would include a navigation system for customers to move around, select items as needed (and remove items), and ultimately, will be able to checkout. This would require state persistence from page to page, and thus an actual full-fledged shopping cart solution.

It is recommended that you choose the e-commerce store software based on features needed along with the number of products contained within your shopping cart.