Parasitology is the study of parasites. It is a branch of biological science that deals with the study of parasites as well as parasitism.
The parasites can be animal parasites such as toxoplasma or human parasites. A parasitologist is a person who has been trained in the study of parasites. Parasitologists study unicellular parasites such as malaria and Leishmaniasis and multicellular parasites such as ascaris lumbricoids, hookworms and flukes.
Parasites cause disease in humans and therefore parasitology is an important tool that helps address the problem.