Merchant accounts and processing gateways are Internet services that enable online processing of credit cards. Online merchant accounts are variations of the traditional credit card processing used by retail stores and phone order houses. A business must qualify for merchant account; each provider has a different set of requirements.
Processing gateways are an intermediary to get card information from your shopping cart to the merchant account. Often processing gateways are packaged with merchant accounts.
A shopping cart is an e-commerce web application that mimics a virtual store. It allows customers to browse and select a product(s), then purchase them at a virtual check out.
Most e-commerce is done with one of the many preprogrammed shopping carts that are available. While these packages should prove adequate for most e-commerce needs, custom programming is always an option for more advanced features.