An antibiotic is any chemical substance derived from bacteria that can slow down or destroy other microorganisms and fight bacterial infections. They usually are semi-synthesized and modify existing bacterium to fight diseases and infections. An antibiotic’s efficacy depends on various factors like host defense mechanism, the infection’s location and properties of the antibiotic. Their indiscriminate use can lead to antibiotic-resistant bacteria. It is therefore imperative to only use antibiotics when necessary and only as per the doctors’ prescription.