Vector (biology)

A vector in biology is an animal on or in which a small living thing gets transported. The vector gets no benefit and sometimes loses fitness by the arrangement.
The term is most used for the transport of parasites and agents of infection or disease. So, deadly diseases, such as malaria and dengue fever, are carried by some mosquitoes.
The study of vectors gives us knowledge about the life cycle of parasitic diseases, and this helps us control those diseases.