When it comes to mathematical structures such as groups or linear orders, we often consider them up to isomorphism. Determining if two structures are isomorphic usually relies on studying their structural properties, and so we can ask the following questions: is there a way to state these properties as formal sentences in some fixed language, and if we have models which satisfy a set of formal sentences, are those models necessarily isomorphic to each other? In this talk, we will briefly cover some basic ideas from model theory and the Scott Isomorphism theorem, which answers the second question above for countable structures.