Is the pole in the outfield called the foul pole or fair post in baseball?

The foul Pole is to aide the umpire in determining if a Baseball hit is fair or foul. The Foul pole is in fair territory, so if the ball hits the pole it is a fair ball, and would count as a home run. If it misses the pole outside of the playing field it is a foul ball (out of play) This is why it is called a 'Foul Pole" It could have been called a Fair Pole as it is in fair territory, but the powers that be decided on "Foul Pole" and "Foul Line"