sir wat is the term pole in chapter parabola in cordinate geometry

Definition of Pole- Let P be a point lying inside or outside of a parabola. suppose a straight line drawn through P intersect the parabola at two point Q and R.Then the locus of the point of intersection of the tangentsto the parabola at the points Q and R is called the Polar of the given point P with respect to the parabola and the point P is called the Pole.