What is a microorganism?

A microorganism is defined as an organism that can be seen only with the aid of a microscope. This classification includes bacteria, viruses, fungi, and protozoa, which are typically too small to be perceived by the human eye. Microorganisms play critical roles in various processes, including decomposition, fermentation, and even disease causation. Understanding their microscopic nature is essential for fields such as microbiology, medicine, and hygiene. The importance of this definition lies in the microscopic scale at which these organisms operate, influencing their behavior, interactions with other organisms, and their impact on health and disease. Recognizing that microorganisms require special tools for observation highlights their distinct characteristics compared to larger, multicellular organisms.