Cad Tab

2D LineWidth – used to set the width of the lines drawn.
Dimensions LineWidth – used to set the width of the lines when dimensioning the part.
The rest are to set default colors for that item.

Here default fonts can be setup for Engraving and Dimensioning.

You may define the number of U and V curves that will represent the surfaces that you will be creating from hereon after. These parameters are only used for display purposes. The precision of the surfaces will not be affected. You can also set default colors for Model Boundary and Surface Holes.