The antimicrobial substances which are active in fighting against bacteria and bacterial infections are called antibiotics. They are highly effective in treating such infections, as they inhibit the growth of bacteria or kill them. Some antibiotics also possess antiprotozoal properties. Such antibiotics are useful in fighting protozoan infections. Antibiotics may also be administered as a preventive measure to at-risk individuals with a weakened immune system, cancer patients, or those undergoing surgery and taking immunosuppressive drugs. Antibiotics are usually taken orally or intravenously. They can also be taken topically in the form of ear drops for ear infections, eye drops for eye infections and in several skin infections. The interaction of alcohol with antibiotics can reduce the effectiveness of antibiotic therapy. Antibiotics are an important area of pharmaceutical science and have undergone rapid development over the past few decades. This book aims to shed light on some of the unexplored aspects of antibiotics and the recent researches in this field. The topics included in this book are of utmost significance and bound to provide incredible insights to readers.