Purification refers to the process of removing impurities or unwanted substances from a substance, such as water, air, food, or chemical compounds. This can be achieved through various methods including filtration, distillation, crystallization, and chromatography among others. The goal is usually to obtain a cleaner, higher quality product that meets certain standards of purity. In some cases, the term may also refer to the act of making something morally or spiritually pure by removing impurities such as sin or evil intentions.