Normalisation on the matrix is just like on an object...
the normalisation vectors are from the vertex points, and you set the XYZ value of these which basically determine direction and length. Think of it as an invisible line from the vertex your working from, to the point you specify.
From that angle from 0° the matrix will smooth itself based on it - it is a good way to create shadows and such
I'd checkout Matrix3D\Exam08.dba as it is quite simple to understand ... that with knowing what a normal is help you to develop your own
Anata aru kowagaru no watashi!