This book can be used as a text-book for teaching of Microbiology at the undergraduate / Bachelor's level (B. Sc. Microbiology). It covers all aspects from history, classification, diversity, methods for studying microbes, application of microbes, etc. in a well defined manner making the subject interesting to the readers. It has book is divided into seven parts and nineteen chapters. The illustrations and other information on contributions by renowned microbiologists is also very interesting. The author is a well-known American Microbiologists who has spent decades on teaching and research in microbial ecology. Enjoy reading!