A contour is defined by nodes which mark the points the contour passes thorugh. When modeling with 3D surfaces, nodes can be added, moved or removed, to better adjust a contour to the limits of the object in the slice.

A path  is defined by a set of nodes that can be connected with each other or not. Each path node can have its own diameter to reflect the path thickness. When modeling with paths, nodes can be added, moved, or removed, and they can also be connected and disconnected.

See also: Overview, Identification of objects.