The common name for the virus that causes chickenpox is varicella-zoster virus (VZV). This highly contagious virus belongs to the herpesvirus family and is responsible for the characteristic itchy rash and blisters associated with chickenpox. The infection typically occurs during childhood, leading to a mild illness characterized by fever, fatigue, and the distinct rash. After recovery, the virus can remain dormant in the body and reactivate later in life, often causing shingles, a painful rash. Vaccines are available to provide protection against chickenpox and reduce the severity of the disease.