I am not trying to "solve a problem" here with this question. I am practicing drawing and try out different tools based on tutorials by Mark Lyons. Right now, I am working with splines to gain some basic skills with curves that are not circles or ellipses. (We do not all live in a rectilinear world.)

I first created a polyline with 5 points and then converted it to a spline using the spline option in the polyline edit tool.

I then traced over the same line using the spline tool. The two curves look very close to the same, but I notice in the properties, the original polyline is still listed as a polyline rather a spline, and the grip handles are offset from the edges, while the spline has grip handles right on the line.

I am looking for a deeper understanding of the two different lines and how best to use them. Any suggestions for reading or viewing that would help me master irregular curves in DraftSight?