Hepatitis B virus (HBV) is a viral infection that primarily affects the liver. It can cause both acute and chronic diseases, leading to liver inflammation, cirrhosis, and even liver cancer. HBV is transmitted through contact with infectious body fluids, such as blood, semen, and vaginal secretions. Vaccination is available and highly effective in preventing HBV infection. The Hepatitis B vaccine is recommended for infants, children, and high-risk adults. Regular screening and monitoring are essential for those at risk, as early detection can help manage the disease and reduce complications.