G2 curves are mathematically smoother than Bézier curves.
To create a G2 curve:
As you enter key points, a rubber-band curve is displayed showing how the curve is forming.
If you want the curvature to be zero at the start point or end points, set the Curvature continuous options on the Curve page of the Options dialog (which is displayed by choosing File > Options > Application Options).
Zero curvature has a flattening effect on the curve.
To edit a G2 curve:
The Manage tab > Curve Type panel > G2 option is selected automatically.
Thisdisplays Bezier curve graphic handles on the curve for editing, but the curve remains a G2 curve if you drag the handles.
You can also edit a G2 curve in the following ways:
This displays Bézier curve graphic handles on the G2 curve. The G2 curve loses its G2 editing ability and can be edited only as a Bézier curve.