Question

the Himalayan have been divided vertically what are they

Answer 1

They are Himadri ,Himachal, Shiwaliks

Answer 2

The Himalayas have also been alienated on the basis of regions from east to west.

The segments has been done on the basis of the rivers flowing in the Himalayan regions. Following are the divisions: -

Punjab Himalayas: This part lies between the Sutlej and Indus. They are also called  Kashmir Himalaya and Himachal Himalaya.

Nepal Himalayas: This part lies between the Tista and Kali rivers.

Kumaon Himalayas: This part lies between Kali and Sutlej rivers.

Assam Himalayas: This part lies between the Dihang and Tista rivers.