We can solve this problem in iterative way also , then what is the significance of using backtracking in this problem ?
Doubt regarding Queen permutations problem
No significance, it can be solved by backtracking also. It does not say it should be solved by backtracking. Its just a famous example for backtracking as we can see the backtracking algorithm in action.
Also backtracking can be optimized using branch and bound and other techniques while iterative is almost brute force