Major objective of this lecture is to present on Human Immunodeficiency Virus (HIV). Here briefly describe on how is HIV spread. HIV stands for human immunodeficiency virus. If left untreated, HIV can lead to the disease AIDS (acquired immunodeficiency syndrome). HIV is a virus that attacks the immune system, the body’s natural defense system. Without a strong immune system, the body has trouble fighting off disease. Both the virus and the infection it causes are called HIV.