The machining can be one way or Zig Zag (bidirectional). If you have a closed geometry and you select "one way machining" will move the tool always around the part in the same direction.
If you have geometry that is not completely closed, then we recommend to set the option Enforce cutting direction (assume closed contours).
Here you can choose between "Zig Zag" and "One way" and activate "Enforce Cutting Direction".
One Way:

Zig Zag:
Here you can see that the contour is not closed. Nevertheless, with enforced cutting direction the contour will be closed in the toolpath.