The rectangular-shaped painted area on either area of the court measured between the baseline and the free throw line one end, and the foul lanes on the other.
The term "free throw lane" is the official term for the lane used by the NBA. In the NBA, the lane measures 16 feet wide (including the foul lanes) and is situated 15 feet from the backboard. It is most often used with respect to free throw shots and offensive players driving to the basket. It is usually referred to as the "key" and colloquially as "the paint."