The active ingredient in Xanax, alprazolam, is a type of drug known as a benzodiazepine. It's used to treat anxiety problems in the short term, especially in persons who are prone to anxiety and panic attacks.
Alprazolam, like many other benzodiazepines, has a long history. The FDA approved it in the early 1980s after it was first patented in the 1970s.
It has grown extremely popular as a prescription drug in the decades since, with tens of millions of prescriptions written in the United States alone.