Isomorphisms between objects that hold in the topological category but not in the smooth category, more concisely referred to as exotic phenomena, are central objects of study in topology and have guided the field's development for more than half a century. In this talk, we give an overview of some basic tools used in the study of 4-manifolds and use them to give an outline of the construction of exotic R4, a smooth manifold which is homeomorphic to the standard R4 but not diffeomorphic.