A model captures a view of a physical system. It is an abstraction of the physical system, with a certain purpose.

This purpose determines what is to be included in the model and what is irrelevant. Thus the model completely describes those aspects of the physical system that are relevant to the purpose of the model, at the appropriate level of detail.

A profile defines limited extensions to a reference metamodel with the purpose of adapting the metamodel to a specific platform or domain.

A constraint is a condition or restriction expressed in natural language text or in a machine readable language for the purpose of declaring some of the semantics of an element.