What is a Metamodel?

Metamodeling can be defined as:

The construction of a collection of concepts (things, terms, etc.) within a certain domain. ... A model is an abstraction of phenomena in the real world, and a meta-model is yet another abstraction, highlighting properties of the model itself.

Metamodels share a lot in common with ontology and their differences are often confused. Whilst a valid metamodel is an ontology, all ontology are not metamodels.

The below representation of the Standard Operating Procedures metamodel represents a small subsection of the broader out-of-the-box metamodel that covers areas as diverse as System Requirements, Corporate Governance, Business Motivation and Knowledge and Training