Parasites are living organisms, which depend on a living host for their nourishment and survival. Their multiplication or development undergo in host. Parasites can be of different types: Ectoparasites, Endoparasites, Free living parasites etc.
Bioterrorism is use of infectious agents or other harmful biological or biochemical substances i.e. from biological source as weapons of terrorism. It is intentional release or dissemination of biological agents. These agents are bacteria, viruses, fungi, or toxins, and may be in a naturally occurring or a human-modified form.