Arrakis, also known as Dune, is a fictional desert planet in the Dune series created by Frank Herbert. It is the only known source of the valuable substance called spice melange, which grants extended life and enhanced mental abilities. The harsh environment features vast sand dunes, extreme temperatures, and giant sandworms that inhabit the desert. The planet is home to the Fremen, a resilient group of people who have adapted to the severe conditions. They have developed unique survival techniques, including water conservation methods and a deep understanding of the desert ecosystem. Arrakis plays a central role in the political and economic struggles depicted in the series.