A virus's primary method of replication is through a process called host cell invasion. The virus attaches to a specific host cell, injecting its genetic material into the host. This genetic material then hijacks the host's cellular machinery to produce viral proteins and replicate its genome. Eventually, new virus particles are assembled within the host cell, which often leads to cell lysis and the release of viruses, allowing them to infect new cells. This process is key to understanding viral pathogenesis and developing treatments.