Yellow Xanax bars refer to a specific form of Alprazolam, which is a prescription medication used to treat anxiety and panic disorders. Alprazolam is a benzodiazepine, and the "bars" refer to the shape of the tablets.

Xanax bars are typically rectangular in shape and can be divided into four sections, with each section containing 2 milligrams (mg) of Alprazolam. The bars are available in different colors, including yellow, white, and green.

It's important to note that using Xanax or any benzodiazepine without a prescription or in a manner not prescribed by a healthcare professional can be dangerous and potentially addictive. Misuse or abuse of Xanax can lead to various side effects and dependency. It's crucial to consult with a healthcare professional if you believe you may benefit from or require this medication.