Secretory granules is a core concept in cell biology and biochemistry focusing on the specialized, membrane-bound organelles within eukaryotic cells responsible for storing and releasing specific molecular cargo via regulated exocytosis. Research within this field investigates their complex biogenesis, cargo sorting and packaging, trafficking, and the precise molecular machinery and signaling pathways that govern their fusion with the plasma membrane in response to appropriate stimuli. The study of secretory granules is significant due to their essential roles in diverse physiological processes, including endocrine secretion, neurotransmission, and immune responses, and their implications in various pathological conditions where regulated secretion is disrupted.