Viral replication is the process by which a virus makes copies of itself inside a host cell. When a virus enters a host, it attaches to the cell's surface and injects its genetic material, which can be either DNA or RNA. This genetic material hijacks the cell's machinery, directing it to produce viral components, such as proteins and new viral genomes. Once enough viral components are produced, they assemble into new virus particles. These new viruses then exit the host cell, often destroying it in the process, and can go on to infect other cells. This cycle of infection and replication allows viruses to spread rapidly within a host organism.