Electronic Commerce (EC) can be defined as the use of modern innovative technologies, mostly based on telecommunications and telematics, to facilitate trade procedures. EC consists of a set of different technologies, including Electronic mail, Electronic Data Interchange (EDI), Electronic Forms, Imaging, Workflow Automation, etc.
Amongst these technologies, EDI has always been considered to be the major driving force of EC.
EDI can be defined as the inter-organisational, application-to-application exchange of business documentation in a standard automated way (Emmelhainz 1993).
EDI can be viewed not only as a technology, but also as a business strategy which can be adopted for productivity increase, lead cycle reduction and other operational and strategic business objectives. These objectives are mainly achieved through the elimination of paper-based business transactions and the bureaucratic procedures that paper usually imposes.
EDI has been increasingly used by businesses during the last years. As the number of companies that were exchanging business documents electronically was increasing, the problem of EDI standardisation became apparent. The roots of this problem can be found on the many proprietary EDI standards that had been developed by EDI users.
Indeed, almost every group of companies that communicated via EDI had developed their own structure for the data to be transmitted. This resulted in isolated ‘islands’ (groups of companies) that could not communicate with each other due to the incompatibility of standards. The growing number of companies using EDI resulted in a growing need for a common standard for structuring EDI data.

B2B is the acronymous for eCommerce Business-to-Business. It's the eCommerce between companies, for example supplyer of a factory.

International Dictionaries are the description and the definition of all components of an EDI message/transaction.
For EDIFACT each dictionary includes: Messages, Segments, Elements, Composite Elements and codes.
For X.12 each Dictionary includes: Transactions, Segments, Elements and codes.

It's a United Nations worldwide EDI standard (Electronic Data Interchange For Administration, Commerce and Transport. United Nations (UN) initiated a project for the development of a world-wide EDI standard in 1985. This standard became known as EDIFACT (EDI For Administration, Commerce and Transport). EDIFACT, although not the only EDI standard that exists, has become the most dominant and important standard and is nowadays being used by thousands of companies worldwide.
A message in EDIFACT terminology is usually the equivalent of a paper-based business document, like an order or an invoice.
Others components are the Segments, the Elements (Simple and Composite) and Codes.

It's the United States and NAFTA countries Electronic Data Interchange standard. It only defines the syntax, development groups, like VICS and TDCC, define the structure exchanged transaction.

It's a set of definitions, with structure depending on EDI Converter, describing the relations and the actions required to transform an EDI File to a local format, and viceversa.
An IDE is generally used to create a mapping, each EDI converter has its approch to do that.