Xanax is a brand name for the drug alprazolam, which belongs to the benzodiazepine class of medications. It's primarily prescribed to treat anxiety and panic disorders, as well as occasionally for other conditions like insomnia and certain types of seizures.

Alprazolam works by enhancing the effects of a neurotransmitter called gamma-aminobutyric acid (GABA) in the brain. GABA is responsible for inhibiting or reducing the activity of neurons, thus producing a calming effect on the central nervous system. By increasing GABA activity, Xanax helps to alleviate symptoms of anxiety and panic.