Washer-disinfectors are automated machines used in healthcare settings to thoroughly clean and thermally or chemically disinfect reusable medical instruments and equipment before sterilization. They play a critical role in the instrument reprocessing cycle, providing a standardized and validated process that is more effective and safer than manual cleaning. Instruments are loaded into racks, and the machine cycles through various stages, including pre-rinse, enzymatic wash, ultrasonic cleaning (in some models), thermal disinfection (using hot water at specific temperatures and durations), and drying. By automating these steps, washer-disinfectors reduce human error, minimize staff exposure to contaminated instruments, and ensure a high level of cleanliness and disinfection, which is essential for the subsequent sterilization process and for preventing healthcare-associated infections.