In the current scenario and development of new course contents as laid down by regulatory bodies for Indian University for undergraduate and postgraduate students of botany, microbiology, biotechnology and biosciences, a basic need to cater the complete syllabus into one umbrella has laid down the foundation stone and blueprint of the present book entitled Essentials of Microbiology. One of the exciting aspects of being involved in the field of microbiology is the accelerating rate of progress. With this in mind, we started off from basic concepts of microbiology to practical applications of microbiological research including history of microbiology, virology, bacteriology, nature of virus, classification of virus, fungi, bacteria and algae. Also, we have highlighted the concepts of microscopy and specimen preparation, tools used in the microbiology laboratory, concepts of virology including virus classification, type and transmission of virus to host, fundamental theory about bacteriology, classification of bacterial, nutritional types, reproduction, bacterial genome, plasmids, mutation, staining and economic importance and mycology.