The interstellar medium (ISM) is the engine driving the cosmic cycle, playing a pivotal role in star formation, stellar evolution, and feedback from supernova remnants. Understanding these processes is key to unraveling the broader evolution of galaxies. In this talk, I will present recent advancements from several studies, shedding light on different stages of the ISM and its impact on galactic ecosystems. First, I will highlight the latest results from the GLOSTAR survey, a comprehensive radio study that uncovers new details about massive star formation and the discovery of supernova remnants in our Galaxy. Next, I will delve into the molecular chemistry of HCNH+, examining its behavior across diverse environments. As a diagnostic tool, HCNH+ provides valuable insights into the early stages of molecular cloud evolution and the effects of feedback from star formation. Finally, I will explore the systematic identification of masers in carbon-rich AGB stars, revealing dichroic masers in circumstellar envelopes of AGB stars. These masers offer a unique window into the later stages of stellar evolution, potentially leading to new insights into stellar physics and evolution. By connecting these topics, this talk aims to provide new facets on the ISM, from the birth of stars to the intricate chemistry of molecular clouds and the final stages of stellar evolution.
