Historically, the boiling of water was the widely used method for water disinfection. In modern times, chemical, physical, ozonation, and distillation are a few methods used for disinfection. Here, chemical and physical are the two popular methods for disinfection of water. The chemical method makes use of chemicals like chlorine, bromine iodine, silver, etc. The physical method, on the other hand, makes use of ultraviolet (UV) lights, gamma-ray irradiation, etc. Out of the two, using UV technology for water disinfection is found to be a more reliable, cost-effective and safe way to purify drinking water.