The first detection of another planet around a Sun-like star marked the beginning of a new era in which our understanding of how planets typically form and the uniqueness of our Solar System were radically upended. We now know that planet formation is incredibly resilient, and produces a diverse myriad of planets around a wide range of stellar types. These remarkable findings tell us that the Solar System is atypical in at least some ways -- the Sun does not host multiple small (1-3 REarth), close-in (< 100 d period) planets, whereas this seems to be the most common outcome of planet formation in the Galaxy. How do these super-Earth and sub-Neptune planets form, what are they made of, how closely (or not) do they resemble Solar System planets? In this talk I will discuss how the community is addressing these questions, and highlight a two-part "concentric" survey I am co-leading to measure small planet compositions in a statistically robust framework. These surveys utilize transiting (TESS, JWST) and radial velocity (Magellan/PFS) techniques to try to connect observed planet distributions to the true underlying populations and the processes that shape them. Such population studies will help hone in on where we should focus future efforts as we move deeper into the era of exoplanet characterization and towards uncovering Earth-like conditions on other worlds.
