The most widely known form of best-first search methods. It uses heuristic function h(n), and cost to reach the node n from the start state g(n). It has combined features of UCS and greedy best-first search, by which it solves the problem efficiently. The shortest path through the search space is found using the heuristic function. The evaluation function is the sum of g(n) and h(n):
Evaluation (objective) function f(n)
An example: Problem and its solution using A*