Hydrogen separation and purification are key steps in making sure that the hydrogen produced from different processes meets the purity standards for industrial and energy use. This chapter gives a clear overview of hydrogen purification technologies. Different methods of separation can be classified into physical and chemical separation methods. Pressure swing adsorption, the most commonly used industrial technique, works on the principle of pressure swing, is discussed in terms of its working principles and practical importance. Membrane-based separation methods, including the historical developments and recent advances in metallic, polymeric, inorganic, zeolite, carbon-based, and mixed matrix membranes are described. Chemical purification methods, such as CO₂ absorption systems, are discussed alongside cryogenic separation, which is a low-temperature physical process. The chapter compares these technologies, pointing out their strengths, weaknesses, and suitable application areas.