Simply selecting a vector object with the Vector Selection tool (single selections only, you can't node edit multiple vector selections), right-clicking, and choosing Node Edit from the drop down menu will get you there. (Alternatively, clicking Node Edit in the Selection Tool Options palette while an object is selected will accomplish the same thing). When an object is being node edited, its fill and stroke attributes disappear, leaving you with the vector essentials of the shape. Those essentials consist of the anchor points and the segments that join them. A single set of anchor points and segments is a contour and an individual vector object may consist of one or more contours and is called a path on the node editing level.
Segments can be either straight or curved, and anchor points or nodes, as they're called in PSP, define segment ends. Paint Shop Pro uses Bézier curves, a compact way of mathematically describing a curved segment, which is based on the location of the nodes that define the segment's ends and on direction lines that describe the angle and length of the curve, called curve handles.
