The Varicella-Zoster Virus (VZV) is a member of the herpesvirus family. It is responsible for causing two distinct diseases: chickenpox (varicella) during initial infection and shingles (herpes zoster) upon reactivation later in life. VZV spreads easily through respiratory droplets or direct contact with the fluid from chickenpox blisters. Once a person is infected with VZV, the virus remains dormant in the nervous system. It can reactivate years later, leading to shingles, which is characterized by a painful rash and blisters. Vaccination against chickenpox is available and helps reduce the incidence of both chickenpox and shingles.