Microbiology is the study of microorganisms that are too small to be seen with the naked eye and require microscopes. Microorganisms play important roles in disease, commercial applications like producing chemicals and enzymes, and food production including fermentation. Studying microbes can provide insights into cellular structure and function in multicellular organisms. There are various types of microbes including bacteria, archaea, fungi, protozoa, algae, viruses, and parasitic worms. Nomenclature systems are used to classify and name microorganisms.