An information model is an object model for a software tool (or a set of software tools). An information model is composed of classes, relationship types, interfaces, property definitions, methods, and collection types.
Information models are stored in the Repository. Each information model describes the types of objects and relationships that are used by one or more software tools. For example, Visual Basic provides an information model named “MdoTypeLib”. This information model describes the forms, controls, and other objects that make up a Visual Basic project. It also describes the relationships between those objects; projects contain modules and forms, forms contain controls, and so on.
The Type Information Model is the information model that the Repository uses to understand all other information models.