In this context a Feature is every single design-step, which can be edited individually and autonomously from the others, before and afterwards designed features.

A complete PARTdesigner Feature is based on a Sketch that needs to be extruded or rotated, either as Base (Solid) or as Cut. This could be a boring or a cutout of a solid, for example.

In addition, there are special features like Blend, Sweep, Pipe, for example.