Bacteriophages are prokaryotic viruses, which multiply in bacteria and archaea. These viruses are important in transferring mobile genetic elements such as virulence and antimicrobial resistance genes to bacteria under a process called transduction. Although bacteriophages have long been addressed with their various medical applications, an exciting application of these viruses is linked to their infection treatment potential. Since antimicrobial resistance is rapidly extending in bacterial populations and no novel antibiotics have been introduced to the market in decades, alternative treatment protocols such as phage therapy must be further supported to secure the future of infection treatments. The present review molecularly introduces bacteriophages and their major applications.