What is in this shampoo that makes my hair feel so nice?

I usually use just cheap stuff which is fine. However, a while ago I got a rash and bought some special shampoo and bodywash for it. Turns out they didn't help (pityriasis rosea - 0/10 would not recommend).

Anyway, that's why I got this shampoo and it makes my hair so incredibly light, soft and silky smooth - more than any other shampoo I've used (I have used expensive stuff in the past) but I don't know why.

Because it's a medicated shampoo I feel like there's probs much cheaper options if I know what ingredients to look for. Can anyone help me identify what it is I'm looking for? What specific ingredient(s) make my hair so soft and clean?

Pics of the ingredients for reference. It's Pharmabanner Folliculitis Shampoo.