HIV stands for Human Immunodeficiency Virus.
It’s a virus that infects the body’s CD4 cells (a type of white blood cell), weakening your immune system and making it more difficult for you to stay healthy. Your immune system is what protects you from illnesses and diseases. HIV makes it harder for the body to take care of itself and can make it easier for you to get sick if you don’t go on treatment.
If someone living with HIV doesn’t get treatment, it can progress to AIDS (Acquired Immunodeficiency Syndrome),
the most serious stage of HIV. AIDS occurs when your body’s immune system is so depleted that it can develop life-serious infections that the body can’t fight off. Thanks to medication and advancements in science, AIDS is far less common in Canada today and people living with HIV on effective treatment can have biological children and condomless sex without passing HIV on to their children or sexual partners!
More on that here
. Today, it's also quite possible to recover from AIDS with medical care and HIV treatment.