In this talk, we will explore the natural topology inherent in the collection of countable structures in a fixed signature. We will describe the Borel structure derived from this topology, which holds a close connection to the infinitary logic Lω1ω through the Lopez-Escobar theorem. Additionally, isomorphism of structures can be understood algebraically, viewing it as an action of the permutation group S∞. We will discuss how maps preserving this algebraic structure correspond to methods of translating between theories in different signatures.