Bacteriophages are viruses that have DNA as their genetic material.
Bacteriophage only attacks bacterial cells and tries to incorporate its DNA with the host's DNA to make multiple copies of them inside the host's body that later on come out of the host's body by rapturing it.
Bacteriophages do not attack the human body, in fact, they are an important part of the human gut that protects it from the attack of deadly bacteria.