Gaurav Kumar Singh has given a good answer. To further clarify, Viruses are not cells. They are vectors for small amounts of genetic material. They are parasitic upon real cells and hijack cells' mechanisms for their own reproduction. read more
Viruses are neither prokaryotic nor eukaryotic. Viruses are in a separate category known as obligate intracellular parasites. By themselves, viruses do not carry the biological material necessary to reproduce; they can only replicate themselves by infecting prokaryotic or eukaryotic cells. read more
Viruses are considered neither a prokaryotic nor eukaryotic; in fact, these are not even considered as living entity because of their failure to reproduce by their own. They are just like infectious biomolecule particles which gets multiplied at the expense of other cellular machinery. Hope it helps. read more