He is a wealthy member in Salem Society. He had a grudge against Francis Nurse for him preventing his brother-in-law from becoming the minister of Salem. He used the witch trials as a way to accuse his rivals and gain all the wealth that they would lose. By accusing others he is able to gain wealth and more land whenever the accused is tried then sent to jail.
Judge Danforth was the deputy Governor of Massachusetts. He believes that he is doing the right thing in Salem by convicting all of those people. He sees himself as an honest and almost savior like person for all the people in Salem at the time.
Giles Corey was "Famous" in Salem for the amount of times he would be in court for filing lawsuits against different people in the town. Giles wife, Martha Corey was accused of witchcraft. Near the end of the play we learned that he was pressed to death for refusing to go to the court. The last thing he said was more weight, they added another rock and he died.