Cleaning: refers to the removal of visible soil and organic material (i.e., dirt, body fluids, etc…) from objects by washing or scrubbing with water and detergents or soaps and rinsing with water. Thorough cleaning is needed before disinfection or sterilization because organic material can decrease the effectiveness of those processes. A detergent is a cleaning agent that does not claim to kill microorganisms.
Disinfection: refers to process of removing many or all microorganisms that can cause disease, except bacterial spores. There are three levels of disinfection, depending on how many organisms are removed: high, intermediate and low. A disinfectant is a chemical or a physical agent (e.g. ultraviolet radiation) that kills microorganisms, but not bacterial spores. Disinfectants are also classified as high-level, intermediate-level, and low-level.
Sterilization: refers to the complete elimination of all forms of microbial life including bacterial spores. Objects can be sterilized by physical processes (i.e., intense steam and pressure or dry heat) or by using certain chemicals.