Colony Forming Units (CFUs) are a measure used in microbiology to estimate the number of viable bacteria or fungal cells in a sample. Each CFU represents a single cell or a group of cells that can grow into a visible colony on a solid growth medium. This method helps researchers and clinicians assess the microbial load in various samples, such as food, water, or clinical specimens. CFUs are important in fields like clinical microbiology, food safety, and environmental monitoring. By counting the number of CFUs, scientists can determine the effectiveness of sterilization processes, the presence of pathogens, and the overall health of microbial communities in different environments.