[Dennis]

Did you read the About Plugins section for the Boolean operation? That gives a very good description of how to use the tool. Have you done any experiments with it? That's often the best way to learn.

Below are some visual examples of how it works. In all of the examples, there is a Sphere that slightly overlaps a Cube. When a boolean operation was performed, the Cube is set as "A" and the sphere is "B". The "Delete" checkbox is checked on both A and B.

In the top image below, there are 4 shapes. In clockwise order from the the top left, they are:

1. Union of A and B
2. Subtract A minus B
3. Subtract B minus A
4. Intersection of A and B

The bottom image is the same, but I included wireframes showing where the original objects were before they were deleted.

Try experimenting with this.

HTH