Finally, it is helpful to understand what all of the terms in the general equation mean. If you think back to the equation of a line () in 2-dimensions you will remember that all the lines with the same slope are parallel. The equation has a similar property. All planes with equations that have the same , , and (or scalar multiples of these constants) will be parallel.

Also, just as the "b" in the equation of a line represents the intercept of a line with the y-axis, the "D" in represents the plane's distance from the origin along its unit normal. Figure 4-6 below illustrates these properties graphically.