Xanax is a brand name for the medication alprazolam, which belongs to a class of drugs known as benzodiazepines. It's primarily prescribed to treat anxiety disorders, panic disorders, and occasionally for other conditions such as insomnia or certain types of seizures.

Xanax works by enhancing the effects of a neurotransmitter in the brain called gamma-aminobutyric acid (GABA), which helps to calm excessive brain activity associated with anxiety and panic disorders. It has a rapid onset of action, which can provide quick relief for acute symptoms of anxiety or panic.