This article approaches the importance of computer animation and simulations in the teaching of physics. A contrast is made between assertions of its defenders and relevant part of its critic disapproval. The aim of this paper is not to claim the abandonment of informatics in education, but instead to encourage a more critical and well-balanced point of view. Thus, educational and epistemological foundations underlying the argumentation of both sides are discussed. The importance of theoretical assumptions and limits of validity is exhibited as a means to enhancing the foundations of computer simulations utilised in physics teaching. The text concludes pointing out the importance of teaching physics by avoiding to exclusively concentrate on the transmission of information and, instead, bearing in mind the construction of knowledge in a wide context which incorporates as contents as their processes of development.