The purpose of this work is to give some definitions and prove some theorems on
projective 3-space S=PG(3,K) over a field K.
Also, the principle of duality in S is given which state that any theorem true in the
projective 3-space concerned with the points, planes and the incidence relation, the same
theorem is true by interchanging "point" and "plane" whenever they occur, where as the
dual of a line is a line.