VZV, or Varicella-Zoster Virus, is a highly contagious virus that causes two distinct diseases: chickenpox and shingles. Chickenpox typically occurs in childhood and is characterized by an itchy rash and flu-like symptoms. After recovery, the virus remains dormant in the body and can reactivate later in life, leading to shingles, which causes painful rashes and nerve pain. Transmission of VZV occurs through respiratory droplets or direct contact with the rash of an infected person. Vaccination against chickenpox is widely recommended and has significantly reduced the incidence of both chickenpox and shingles.