A message is a set of data passed from one application to another. A message can be modelled by a message definition which describes the structure and content of the message.
A message definition consists of elements organized into a logical structure agreed by the sending and receiving applications. This logical structure can be modeled using the Message Definition editor, so that messages can be parsed into a logical tree and manipulated easily.
In the message model, a message is always based on a global element. The global element's type describes the contents of the global element, and therefore describes all of the content of the message.
If necessary, a message definition can contain other message definitions. This is necessary for modeling certain large and complex messaging standards like SWIFT and EDIFACT.
Messages are identified by their name or an alias. The alias is an optional user-specified string to identify the message. The name or alias of a message must be unique within a message set.