The message model consists of the following components.
See Message modeling concepts for a summary of these components, and the relationship between them. See Related Concepts below for a detailed description of each component.
The majority of your model content is described by message definition files. These files use XML Schema to represent your messages. XML Schema is an international standard that defines a language for describing the structure of XML documents. It is ideally suited to describing the messages that flow between business applications, and it is widely used in the business community for this purpose. WebSphere® Message Broker uses XML Schema to describe the structure of all kinds of message format, not just XML.
Each message definition file describes both the logical structure of your messages, and the physical formats that describe the appearance of your message bit stream during transmission. If you are using the MRM or IDOC domains, you must provide physical format information. This tells the parser exactly how to parse the message bit stream. If you are not using the MRM or IDOC domains, physical format information is not needed
To understand the different ways that you create and populate message definition files, see Ways to create message definitions. See Physical formats in the MRM domain for a description of the physical formats that are available to you.