Viruses are classified as non-living. Although they have DNA or RNA as genetic information, a protein coat, and some, a lipidic envelope, they do not have the machinery to multiply on their own and therefore are non-living. A virus is simply an infectious agent that, through different ways, many times only by releasing its genetic information inside the cell, replicates using other living-cells machinery. Viruses are able to infect any type of cell.