HIV stands for human immunodeficiency virus. It's a virus that damages your immune system and makes it harder for you to fight off infection and disease. AIDS stands for acquired immune deficiency syndrome. This term is used to describe a variety of dangerous (and potentially life threatening) illnesses that happen when your immune system has been weakened by HIV.
Currently there is no cure for HIV, however drug treatments now mean most people with the virus are able to live long, healthy lives. An early diagnosis and effective treatment allows most people with HIV to avoid any AIDS-related illnesses. HIV has been around for many decades, however it was only discovered in the 80s. Back then the disease wasn't fully understood and the diagnosis came with a great deal of stigma. Today, we know much more.
Then, AIDS was a common outcome of a HIV positive diagnosis - today, thanks to advances in our understanding and drug treatments, it is less common.