Purification methods are techniques used to remove impurities or contaminants from substances, ensuring their safety and effectiveness. Common methods include filtration, where a barrier separates solid particles from liquids, and distillation, which involves heating a liquid to create vapor and then cooling it to collect purified liquid. Other methods include chromatography, which separates components based on their movement through a medium, and adsorption, where impurities adhere to a solid surface. Each method is chosen based on the specific properties of the substance being purified and the nature of the impurities present.