Sterilization is the killing or removal of all microorganisms, including bacterial spores, which are highly resistant. Depending on the material, sterilization can be achieved by autoclave, hot-air oven, ethylene oxide gas, or filtration.
Disinfection is the killing of many, but not all, microorganisms. During disinfection, pathogenic bacteria will be killed but some microorganisms including spores may remain viable. Use of disinfectant varies depending on the purpose of use i.e., inanimate objects or skin surface. Some of the popular disinfectants are phenol-containing compounds, quaternary ammonium compounds, alcohol (ethanol), chlorine, iodine, etc. Disinfectants used on the surface of the skin or mucous membrane are called antiseptics.