• The Thar Desert or Great Indian Desert is the world’s ninth-largest desert. 
• The Great Indian Desert spreads mostly along with the states of Rajasthan and extended in the different portions of Haryana, Punjab and Rann of Kutch in Gujurat.
• It forms a significant portion of western India and covers an area of about 200,000 km² to about 238,700 km². 
• The Desert National Park is situated in the City of Jaisalmer. 
• It has a collection of fossils of animals and plants 180 million years old. 
• Most of the Great Indian Desert is located to the southwest of the north Indian plains and to the west of Aravalli Mountain, this region is also known as the Rajasthan plain. 
• There are a few saline lakes such as Panch Pardra, Sambhar, Didwana, etc.
• The region experiences an extreme type of climate.
• Thar is the most populous desert in the world with a human density of around 84 per sq. km.
• More than 80% of people live in villages or scattered settlements called ‘dhanis’. 
• Barchans (crescent-shaped dunes) cover larger areas but longitudinal dunes which are prominent along Indo-Pakisthan Boundary.  
• Luni is the largest river in this region.
• The Great Indian Desert is divided such as:

Marusthali

• The desert is characterized by shifting sand dunes. 
• It is covered with rocks, sands and dunes in the region of the extreme west.
• The dunes are locally known as ‘Dhiran’ and the blowout depressions are known as “Dhand”.

Bagar

• The Bagar is the big desert of the grassland.
• Bagar is lying east of Marusthali, i.e. along Luni Valley.
• There are grasslands with little sand.
• It is the marked development of agriculture with irrigation for Rajasthan.

Rohi

• Rohi is the small fertile food plains of small streams, which is originated from the western slope of Aravalli.
• It is located to the east of Bagar.