How are Arunachal, Himachal, Purvachal and Uttarakhand Himalayas different from each other?

Arunachal Himalayas
(i) These extend from east of Bhutan to Diphu pass in East.
(ii) Important peaks are-Kangtu and Namcha Barwa,
(iii) They are bisected by fast flowing rivers forming deep gorges.
(iv) Brahmaputra flows through deep a gorge after crossing Namcha Barwa.
(v) Subansiri, Dihang, Dibang and Lohit are the important rivers. Perennial rivers have high rate of fall which helps to generate hydro-electricity.
The Himachal and Uttarakhand Himalayas-
(i) It lies between river Ravi and Kali in the east.
(ii) Northernmost part is the extension of the Ladakh desert
(iii) All these ranges Nimadi, Himachal and Chivalric are prominent here.
(iv) Hill stations are Dharamshala, Mussoorie, Shimla, Ranikhet and Almora.
(v) Shiwaliks are important for dun formation. For example- Kalka dun, Nalagarh dun (Dehradun is the largest-dun, its length is 35-45 km and width is 22-25 km.)
(vi) Tribes common are Dhotia.s which migrates to higher region in summer.
(vi) Valley of flowers. Nanda devi is also situated here. Gail.s, the Manipur Pilgrimages common are Kedarnath, Badrinath, Hemkund Sahib.
The Eastern Hills and mountains or Purvachal.
(i) General alignment from the north to south direction.
(ii) In north, they are known as Patkai Bum, Naga hills, the Manipur hills and in the south, as Mizo or Lushai Hills. This forms Purvanchal range.
(iii) Most of these ranges are separated from each other by numerous small rivers.
(iv) The barak is an important river in Manipur and Mizoram.
(v) Mizoram has a large lake known as .loktak lake is made up of sof unconsolidated deposits..
(vi) Mizoram and Manipur are tributary of Barak river, which is the turn tributary of Meghna rivers in eastern part of Manipur are tributaries of Chindwin which is in turn is a tributary of Ireawady of Myanmar.