 The most basic structuralist conception of scientific representation asserts that scientific models, understood as structures, represent their target systems in virtue of being isomorphic to them. An isomorphism between two structures \(\mathcal{S}\) and \(\mathcal{S}'\) is a bijective function from \(U\) to \(U'\) that preserves the relations on \(U\) (and inversely, the relations on \(U'\)). An isomorphism associates each object in \(U\) with an object in \(U'\) and pairs up each relation in \(R\) with a relation in \(R'\) so that a relation holds between certain objects in \(U\) iff the corresponding relation holds between the objects in \(U'\) that are associated with  them.[9]  Assume now that the target system \(T\) exhibits the structure \(\mathcal{S}_T\) and the model is the structure \(\mathcal{S}_M\). Then the model represents the target iff it is isomorphic to the target: