What is a 'Pin down'

Some ideas: The screener positions himself near the baseline while the player who will receive the screen (usually a shooting guard or a small forward) positions himself higher up, near the three-point line. When the player with the ball decides to pass to the player who will receive the screen, the player who will set the pin down quickly moves up the court and sets a solid screen against the defender of the receiving player. The receiving player uses the screen to get free from his defender and look for an open position on the perimeter. He can receive a pass and have an open shot opportunity or look for additional options, such as cutting to the basket or passing to an open teammate.