Geographically, the Indo-Gangetic Plain is a “foredeep” that formed as a result of the Himalayan uplift. As the mountains rose, a massive basin was created between the Himalayas and the Peninsular Plateau. Perennial rivers flowing from the mountains carried enormous loads of eroded material, depositing them in this basin. This continuous process of alluviation created a flat, fertile expanse. It is characterized by features like Bhangar (older alluvium) and Khadar (newer alluvium). This plain is the agricultural backbone of South Asia, supporting one of the highest population densities in the world due to its immense soil productivity.