The Axes and Origin

                             

An effective way to picture the three Cartesian axes shown in Figure 1 is by learning the right-hand rule. Turn your right palm up, and then extend only the thumb and forefinger. This forms an "L," with the middle finger up to the ceiling, as in Figure  The thumb is the X-axis, the forefinger is the Y-axis, and the elevated center finger is the Z-axis.

                                      The point where all three axes meet is called the origin. This occurs roughly in the palm of your hand, or the corner of the box. The origin is important because it is the central reference point for all the dimensions. You can think of the origin as the "You are here!" dot on a map. Within the Cartesian system, any specific location can be described by its place along the three axes and the distance from the origin.