The term Electronic commerce (or e-Commerce) refers to the use of an electronic medium to carry out commercial transactions. Most of the time, it refers to the sale of products via Internet, but the term eCommerce also covers purchasing mechanisms via Internet (for B-To-B). Explaining e-Commerce A client who purchases on the Internet is called a cyberconsumer. E-Commerce is not only limited to online sales, but also covers: preparation of estimates online; consulting of users; provision of an electronic catalog; access plan to point of sales; real-time management of product availability (stock); online payment; delivery tracking; and after-sales service. In certain cases, electronic commerce makes it possible to highly customize products, in particular when the electronic commerce site is linked with the production system of the enterprise (e.g. business cards, customized items such as T-shirts, cups, caps, etc.) Finally, insofar as electronic services and products are concerned (MP3 files, software programs, e-books, etc.), electronic commerce makes it possible to receive the purchase in a very short time, if not immediately. Online Stores Most electronic commerce sites are online stores that have at least the following elements at the front-office level: an online electronic catalog listing all products for sale, their price, and sometimes their availability (product in stock or number of days before delivery); a search engine, which makes it possible to easily locate a product via search criteria (brand, price range, key word, etc.); a virtual caddy system (sometimes called virtual cart), which is the heart of the e-commerce system as it makes it possible to trace the purchases of the client along the way and modify the quantities for each reference; secure online payment (accounting) is often ensured by a trusted third party (i.e. a bank) via a secure transaction; and an order tracking system, which allows for the tracking of order processing and, sometimes, provides information on the pickup of the package by the shipper. A back office system allows the online dealer to organize its offerings online, modify prices, add or remove product references, as well as manage and handle client orders.