The discussion of nuclear structure in the recent Long Range Plan for Nuclear Physics is built around the twin themes of the remarkable simplicities and regularities exhibited by atomic nuclei on the one hand, and understanding how to construct these complex many-body systems in terms of their constituents and their interactions. Simply put, these refer to the macroscopic or collective description of nuclei in terms of their shapes and symmetries, and to the microscopic understanding of how, where, and why these structures arise. There has recently been a wealth of new geometrical descriptions of nuclei and their structural evolution. At the microscopic (femtoscopic, really) level this evolution depends on the competition of short range like-nucleon residual interactions (pairing) and the (valence) proton-neutron (p-n) interactions. It is possible to measure these interaction strengths empirically in terms of double differences of nuclear masses. This has led to a simple understanding of how these interactions drive the development of collectivity and deformation in nuclei. Moreover, it has recently been possible to calculate these interactions using Density Functional Theory, which has led to several new avenues of investigation. These topics will be discussed.