A bacteriophage is a virus that can infect and replicate only inside a bacteria. They can kill bacteria without any negative effect on human or animal cells. They are referred to as phages and are the most common biological entities found on Earth. Bacteriophages vary in size, morphology, and genomic organization. Many phage-based technologies and therapies have been developed, especially in antibacterial treatments. There are several potential advantages of bacteriophages over antibiotics in terms of treating bacterial infections. Some of the benefits of bacteriophages are specificity of action (i.e., they kill only the pathogen they recognize), a considerable spectrum of activity, higher tolerability, and ease of administration. The results of various in-vitro studies have shown that bacteriophages could also be effective in the treatment of cystic fibrosis (CF) disorder. This book is a compilation of chapters that discuss the most vital concepts and emerging trends in the study of bacteriophages. It traces the recent developments in bacteriophage biology, technology and therapy. With state-of-the-art inputs by acclaimed experts of this field, this book targets medical students and professionals.