Cartesian Equation of a Plane

ok so nothing new... the cartesian equation of a plane is given by:

Ax+By+Cz=D

what i'd like to know.. is what significance does D have? does it have anything to do with the distance from Origin?

thanks

The distance of the plane from the origin is $\displaystyle \frac{|D|}{\sqrt{A^2+B^2+C^2}}$.