Question: what is the significance of the sahara desert?
Answer: the largest hot desert

The Sahara (Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrāʼ al-kubrá, 'the Great Desert') is the largest hot desert and the third largest desert in the world after Antarctica and the Arctic.  Its area of 9,200,000 square kilometres (3,600,000 sq mi) is comparable to the area of China or the United States. The name 'Sahara' is derived from dialectal Arabic word for "desert", ṣaḥra (صحرا /ˈsˤaħra/).