The Sahara Desert formed over millions of years through a complex process of geological and climatic changes. Initially, the region was lush and green, with abundant vegetation and water sources. However, due to tectonic shifts and changes in Earth's orbit, the climate gradually became drier, leading to the desertification of the Sahara. Today, the desert is characterized by vast stretches of sand dunes, rocky plateaus, and sparse vegetation, shaped by wind and erosion over millennia.