The aim of this paper is to show the results of a review of the literature related to the teacher's knowledge about scientific models.For that, we provide with real data from several research.As a result, we can say that the knowledge of teachers about the nature and functions of scientific models is, in many cases, confuse or incomplete.But it is still a necessary concept for them to know.For this reason, we have analyzed possible sources which can be someway responsible for the difficulties that teachers suffer when trying to understand the concept.We have identified two: the many characteristic that are assigned to the concept when we look at it from an epistemological perspective; and the multiplicity of typologies that the authors describe to classify the different models.We try to avoid these two causes resorting to an ontological definition of scientific model.Ontology provides us with an unambiguous, general, independent, and eco-37