Compare between model and meta model.
Answers
Models…
Before we go into the details of modeling, we need to define what we mean by the term “model”: A model is an external and explicit representation of a part of reality as seen by the people who wish to use that model to explore, to redesign and to transform that part of reality.
External, because they are externalized on some medium such as paper, a whiteboard or some diagramming or modeling software on a computer.Explicit, because they are explicitly characterised as models by their creators and not implicit in some verbal description.
Metamodels
A metamodel is itself a model that is used to describe another model using a modeling language. The term “meta” (“behind” or “above” something) is therefore relative – depending on the perspective, a model is either a model or a metamodel. It is important to note that a metamodel is not an aggregated or less detailed view of another model: A metamodel is a model at a different level of abstraction that makes statements about the structure of another model (or a whole set of other models), without making statements about their content.