Core-collapse supernovae are cataclysmic explosions of massive stars that enrich their surroundings with heavy elements and dust and profoundly affect the interstellar media in which they evolve. These supernovae leave behind compact objects whose high densities and magnetic field strengths represent matter under some of the most extreme conditions known. Yet the details of how the explosions occur – from how the final stages of progenitor evolution proceed to which massive stars produce which subtypes of supernovae – are still not entirely understood. Supernova remnants, the nearby remains of supernova explosions, allow us to spatially resolve and study the expelled material and the circumstellar environment in detail. I will describe how multi-wavelength observations of these remnants can inform us about their stellar progenitors and supernova explosion properties. I will conclude with highlights from new JWST observations that reveal supernova remnants in unprecedented detail.