Bernard is the son of Charley, Willy's neighbor. When Bernard is a teenager, he tries to help Biff with his math, but even then Willy is contemptuous of Bernard because he isn't an athlete. Willy calls him "an anemic." Bernard contrasts sharply with Willy's sons because he is a good student and works hard in school.
As a young man, Bernard becomes a lawyer. Willy is impressed when he discovers in Act II that Bernard is going to argue a case before the Supreme Court. Bernard has become quietly successful while Biff has accomplished nothing in Willy's view. The former "anemic" is now the winner.