Schematic diagram of the neutrino reheating phase during a CCSN explosion. (This figure is originally from Bruenn et al. 2009 and reproduced here with permission from AIP Publishing.) Neutrinos emanate from the neutrinosphere—a proxy for the surface of the proto–neutron star (gray shaded region)—and the cooling layer above it. Neutrino heating mediated by neutrino–matter interactions in the gain layer between the gain radius and the shock provides energy to reinvigorate the stalled supernova shock. During shock revival, the flow below the shock may be modulated by neutrino-driven convection and the standing accretion shock instability (SASI).