What exactly is a virus? A virus is a microscopic infectious agent that can only replicate inside the living cells of a host organism. Unlike bacteria, viruses aren't considered fully alive—they can't reproduce, grow, or carry out metabolic processes on their own. Structurally, a virus consists of genetic material, either DNA or RNA, enclosed in a protective protein shell called a capsid. Some viruses also have an outer lipid envelope. Once inside a host cell, the virus hijacks the cell's machinery to make copies of itself, often damaging or killing the cell in the process. Viruses can infect humans, animals, plants, and even bacteria. Click Here......See More