Over the past decade, gamma-ray observations from space-based instruments such as Fermi-LAT and ground-based arrays including H.E.S.S., MAGIC, and VERITAS have provided an increasingly detailed view of supernova remnants (SNRs). Several dozen SNRs have now been detected across the GeV–TeV energy range, revealing a diverse population shaped by their surrounding environments and evolutionary stages. The catalog of gamma-ray bright remnants continues to expand with new discoveries. Observations by HAWC and LHAASO have even identified a few Galactic PeVatron candidates, although a direct link to individual SNRs remains under investigation.

Beyond isolated remnants, gamma-ray detections from novae, as well as from star-forming regions and stellar clusters, underscore the ubiquity of shock-powered emission in explosive and turbulent environments. In particular, the collective action of multiple supernovae and stellar winds within massive star-forming regions appears capable of sustaining efficient particle acceleration, potentially bridging the gap between classical SNR shocks and Galactic PeVatrons. This review highlights recent gamma-ray results that provide new insight into the radiative signatures, acceleration efficiency, and energetic processes associated with shocks in both isolated and collective astrophysical systems.