Hepatitis B Virus (HBV) is a virus that primarily affects the liver, causing inflammation and potentially leading to serious health issues. It is transmitted through contact with infected bodily fluids, such as blood, semen, or vaginal secretions. Common modes of transmission include unprotected sex, sharing needles, and from mother to child during childbirth. Infection with HBV can be acute or chronic. Acute infections may resolve on their own, while chronic infections can lead to long-term health problems, including liver cirrhosis and liver cancer. Vaccination is available and effective in preventing HBV infection, making it an important public health measure.