Curve Lines can be drawn that have multiple smooth inflections between Start and End Points (sinusoid shapes).
Curve Lines are controlled by pairs of Control Points and a single pair of Start and End Points. Control Points and End Points can be stretched to reshape the Curve Line later.
Each Segment of the Curve Line will become a separate object.
Use Polyline if you want to draw a single object with multiple curved segments.
Curve and Straight lines can not be mixed in the same Polyline.
Figure 10.18 Curve Line with Control Points and Start/End Points