A two-dimensional polyline is a parametric entity that specifies a set of two-dimensional vertices and a set of linear or arc segments connected in a single curve in a plane. A two-dimensional vertex is an individual entity that specifies a position, type, and geometrical parameters.

A three-dimensional polyline is a parametric entity that specifies a set of three-dimensional vertices and a set of linear segments connected in a single curve in world space. This entity stores three-dimensional vertices, which are the individual entities that specifies a position, type, and some geometrical parameters.

For more details, see the following topics:

Overview of Two-Dimensional and Three-Dimensional Polylines

Types of Polylines and Vertices

Specific Properties of Polylines

Computed Properties of Polylines

Editing Vertices of Polylines

Editing Segments of Polylines

Example of Working with Polylines

OdDb2dPolyline Class and OdDb3dPolyline Class in API Reference

Sample project of working with polylines is located in the Drawing\Examples\DevGuide\OdPolylinesEx subdirectory of the ODA installation folder.