HIV and AIDS are related but different. HIV is the virus that weakens the immune system, and AIDS is the late stage of HIV infection defined by specific opportunistic infections. There are four stages of HIV infection from initial infection to AIDS. HIV is transmitted through bodily fluids and can be prevented through abstinence, monogamy, protected sex, and sterile needles. While there is no cure for HIV/AIDS, antiretroviral drugs can control the virus and prevent transmission.