Best first search
In your question, when you start from Arad you can go either straight to Sibiu (253km) or to the Zerind(374km) or Timisoara(329km). In this case, both algorithms choose Sibiu as it has a lower value f(n) = 253.
Now you can expand to either state back to Arad(366km) or Oradea(380km) or Fargas(178km) or Rimnicu Valcea(193km).
For best first search Faragas will have lowest f(n) = 178 but A* will have Rimnicu Vilcea f(n) = 220 + 193 = 413 where 220 is cost of getting to Rimnicu from Arad (140+80) and 193 is from Rimnicu to Bucharest but for Faragas it will be more as f(n) = 239 + 178 = 417.
So now clearly you can see best-first is greedy algorithm because it would choose a state with lower heuristics but higher overall cost as it doesn't consider the cost of getting to that state from the initial state.
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