My bad, I thought the question was about post-up moves, not about facing up.

To "post up" is to establish a position in the low post, the area near the basket below the foul line, usually in order to take advantage of a smaller defender. The offensive player usually faces away from the basket, so that his body can protect the ball from the defender. From this position, options such as spinning or backing down the defender to close in to the basket for better scoring opportunities become available to him.

I must have been mistaken...