Mechanics of Viral Infection
Viruses are obligate intracellular parasites that usurp the metabolic processes of the hosts they invade for their own replication purposes.
In brief, viruses must attach to and penetrate susceptible host cells—that is, cells that have appropriate receptors for viral binding and the necessary intracellular machinery for viral replication.
Next, the virus uncoats, a process by which the viral DNA/RNA separates from the viral capsid. The virus then exploits the host's RNA/DNA/protein synthesis machinery.
Viral subunits are then assembled, allowing the progeny viruses to be released, as the host cell disintegrates.