"A* star is better than Dijkstra" is a statement equal to "A hammer is better than a nail pistol". You can compare these two only in terms of their results. And the results of both of them are equally good. Other than that they are totally different. A* is a heuristic search. Dijkstra is pure graph theory. In most cases the implementation of dijkstra algorithms is a little more slim than the A* ones. But there are even hundreds of variations of the dijsktra algorithm. As a rule of thumb A* can get faster results when you have really many nodes to search (that is why it uses heuristics). In scenarios where you've got medium or low number of nodes the choice of algorithm is a purely technical decision.