Can someone tell me the different between datatypes : Polyline and PolylineCurve?
Is there any difference which one is faster?
Polyline inherits from Rhino.Collections.Point3dList and PolylineCurve inherits from Rhino.Geometry.Curve. Meaning that they expose different properties/methods from their parents. Which is faster would depend on the use case. Hope you’re doing well 
Hi Anders, Good to hear from you
Polyline is some sort of array of points, I think in my case it is better to use this.
I see that methods within these types are totally different.
Thanks it is clear now.
Yup, it’s basically a point array with some additional methods (GetSegments, CenterPoint, PointAt etc.). Note that PointAt works a bit differently than we’re used to from curves (with “the integer part of the parameter indicates the index of the segment”). I like Polylines a lot 