The geographical term for regions that receive less than 10 inches of rainfall per year is deserts. Deserts can be hot, like the Sahara, or cold, such as the Antarctic Desert. They are characterized by their arid conditions, extreme temperatures, and scarce vegetation. Deserts are crucial for studying climate adaptations and contribute to environmental diversity. They often feature specialized flora and fauna that have adapted to survive in harsh conditions, making them unique ecosystems within the broader context of global geography.