A virus (from the Latin virus meaning toxin or poison) is a sub-microscopic infectious agent that is unable to grow or reproduce outside a host cell.

Meanwhile viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer.

LiveScience.com explains human viruses , viruses in the human body , common human viruses , types of human viruses and human papilloma viruses

Viruses Properties: They are obligate intracellular parasites. Probably there are no cells in nature that escape infection by one or more kinds of viruses. (Viruses that infect ...

References. Calisher, C. H., M. C. Horzinek, M. A. Mayo, H. W. Ackermann, and J. Maniloff. 1995. Sequence analyses and a unifying system of virus taxonomy - consensus via consent.