You create 2D profiles on workplanes, and then you move or rotate these profiles relative to the workplane to create or modify a 3D part.
You can think of the basic creation process like this:
1. Position a workplane in 3D space.
2. Draw the profile of what you want to create on the workplane, which is acting like a sheet of transparent sketch paper.
3. Use this 2D profile to create the new 3D part, using either Extrude, Turn, or one of the freeform operations.
The figure below shows an example of turning.
Workplanes are also used to machine a part after it has been created. The process when creating and machining is to position a workplane, draw a profile, then carry out a machining operation. The figure below shows an example of punching.
