With Every state node/state ‘n’ and Heurist function H(n) is associated maps the state of with a real value of a number of an estimation of the distance to reach the goal through ‘n’.

Heurist is of two types

1 . Admissible

2. Non – Admissible

Admissible :

it is an under estimate

The estimated cost should be less than actual cost

H(n) < Actual cost

Non Adminsable

It is an Over Estimate

The estimated cost should be greater than actual cost

H(n) > Actual Cost