to access and modify the source code of the entire online store. Licensed software: The software is downloaded and then installed on a Webserver. This is most often associated with a one-time fee, 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. Hosted service: The software is never downloaded, but rather is provided by a hosted service provider and is generally paid for on a monthly or 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 (often known as themes) that a user can choose from to customize the look and feel of their website. Predefined templates limit how much users can modify or customize depending on what platform the template is used on. Some platforms like Shopify, BigCommerce or ShopWired allow users to edit the individual files that their template is made from, often using a templating language to render dynamic content (such as Shopify's Liquid or Twig). Hosted services offer the advantage of having the vendor continuously keep the software up to date for security patches as well as adding new features. PCI Compliance The PCI security standards are a blanket of regulations set in place to safeguard payment account data security. The council that develops and monitors these regulations is composed of the leading providers in the payment industry: American Express, Discover Financial Services, JCB International, MasterCard Worldwide, and Visa Inc. Essentially, they define the best practices for storing, transmitting, and handling of sensitive information over the internet. Visa Inc. can hold shopping cart software providers responsible for liability that may occur as a result of non-compliance to Visa's regulations. For this reason, Visa Inc. may require that online merchants use shopping cart software providers from their list of PCI DSS-validated service providers. See also Comparison of shopping cart software References E-commerce software