Microbiology is the study of microscopic organisms, either unicellular, multicellular, or acellular. Microbiology includes the disciplines virology, mycology, parasitology, bacteriology, and so on. Eukaryotic microorganisms exhibit cell organelles and include fungi and protists, whereas prokaryotic organisms which all are microorganisms are conventionally classified as lacking organelles and include eubacteria and archaebacteria. This review mainly discussed on virology, food microbiology and immunology