Disinfection refers to the use of physical, chemical or biological methods to kill or remove a variety of pathogenic micro-organisms in the external environment, so that it does not cause disease to the number of general to kill or remove 90% of the rate of qualification. The so-called "external environment" includes inanimate liquids, gases and solid surfaces, but also includes the body surface and superficial cavities of living animals. Veterinary disinfection is in the "prevention-oriented" premise, in order to reduce the breeding environment of pathogenic microorganisms on the animal body invasion, to avoid or control the occurrence and prevalence of animal diseases, the breeding environment, utensils, animal body surface or animal products of microorganisms to kill or remove the method. Chemicals used to kill pathogenic microorganisms in the external environment are called disinfectants. Instruments that are physically disinfected or that produce chemical disinfectants are called sterilizers.
Sterilization is the process of killing all microorganisms in the external environment by physical or chemical means. Sterilization is an absolute concept and is the most thorough disinfection. Chemical substances that can kill all microorganisms in the external environment are called sterilizing agents. Physical sterilization equipment is called a sterilizer.