Autophagy is a highly conserved process in eukaryotes where cytoplasmic components, including excess or aberrant organelles, are sequestered into double-membrane vesicles and delivered to the lysosome/vacuole for degradation and recycling. This process plays crucial roles in various biological events such as adaptation to environmental changes, cellular remodeling during development and differentiation, and lifespan determination. Autophagy also has protective roles against certain diseases, although it can contribute to some pathologies. The molecular machinery of autophagy, initially identified in yeast, has been extensively studied in model systems, revealing the involvement of numerous genes and proteins. The review focuses on the molecular mechanisms and machinery of macroautophagy, including the regulation and induction of autophagy, conjugation systems, retrieval processes, and vesicle biogenesis. Key components such as the Atg1-Atg13 kinase complex, Atg8-PE conjugation system, and phosphatidylinositol 3-kinase complexes are discussed, highlighting their roles in autophagy. The review also addresses the fusion of autophagosomes with the lysosome/vacuole and the breakdown of the vesicle. Despite significant progress, many questions remain, particularly regarding the steps of vesicle formation and the origin of the lipid membrane.Autophagy is a highly conserved process in eukaryotes where cytoplasmic components, including excess or aberrant organelles, are sequestered into double-membrane vesicles and delivered to the lysosome/vacuole for degradation and recycling. This process plays crucial roles in various biological events such as adaptation to environmental changes, cellular remodeling during development and differentiation, and lifespan determination. Autophagy also has protective roles against certain diseases, although it can contribute to some pathologies. The molecular machinery of autophagy, initially identified in yeast, has been extensively studied in model systems, revealing the involvement of numerous genes and proteins. The review focuses on the molecular mechanisms and machinery of macroautophagy, including the regulation and induction of autophagy, conjugation systems, retrieval processes, and vesicle biogenesis. Key components such as the Atg1-Atg13 kinase complex, Atg8-PE conjugation system, and phosphatidylinositol 3-kinase complexes are discussed, highlighting their roles in autophagy. The review also addresses the fusion of autophagosomes with the lysosome/vacuole and the breakdown of the vesicle. Despite significant progress, many questions remain, particularly regarding the steps of vesicle formation and the origin of the lipid membrane.