Asana - categories of Asanas (alignment / benefits / contraindictions)

Question 1

How many categories are there

Answer 1

7

Question 2

what are these

Answer 2

1. standing open hip postures
2. standing closed hip postures
3. inversions
4. balancing postures
5. arm balances
6. forward folds
7. backbends

Question 3

what is a benefit of a backbend

Answer 3

they open up the shoulders and chest

stimulates nervus system

increases flexability