Cleaning is the physical removal of foreign material and organic material. Cleaning physically removes rather than kills microorganisms. It is accomplished with water, detergents, and mechanical action.
Sanitizing lowers the numbers of germs on surfaces or objects to a safe level, as judged by public health standards or requirements. This process works by either cleaning or disinfecting surfaces to lower the risk of spreading infection.
Disinfection is the inactivation of disease-producing microroganisms. Disinfection does not destroy bacterial spores.
Sterilization is the level of reprocessing required when processing critical medical equipment/devices (equipment or devices that enter sterile tissue). Sterilization results in the destruction of all forms of microbial life including bacteria, viruses, spores and fungi.