Himadri, Himavan, and Himachal are other names for the Himalayan Mountains. The Himalayan mountain ranges are the world's newest and highest mountain ranges. The major axial range of the main Himalayas alone runs about 2,400 kilometres (nearly 220 longitudes) from the Indus canyon in the west to the Brahmaputra gorge in the east, indicating the scale of their size.

The Himalayan ranges in width from 500 kilometres in Kashmir to 200 kilometres in Arunachal Pradesh. The Himalayan mountain range covers almost 5 lakh square kilometres. The Pamir, sometimes known as the "Roof of the World," is the connecting link between the Himalayan Mountains and Central Asia's highlands. The Himalayas extend eastward from the Pamir in the shape of an arcuate curve that is convex to the south. The Himalayas' southern limit is strongly defined by the foothills (300 m contour line), whereas the northern barrier is hazy and blends with the Tibet Plateau's edge.

Because of their great altitude, steep gradient, snow-capped summits, extensively dissected topography, juvenile drainage, complicated geological structure, and rich temperate flora in subtropical latitudes, the Himalayas have developed a distinct identity.

The Himalayan mountain ranges contain the world's highest peaks. There are 14 summits higher than 8,000 metres and 20 peaks higher than 7,500 metres. All but two of Asia's 94 peaks above 7,300 metres are found in the Himalaya and Karakoram ranges. Hundreds of peaks over 7000 metres exist, and numerous summits above 6000 metres have yet to be properly counted and mapped. Many of them have never had their names given to them.