There are 3 different Boolean Operations that you can apply to a set of selected 3D objects:
- Subtract - Removes the overlapping parts from the base object. The base object is always the bottom layer and the top layer is subtracted from it.
- Intersect - Creates an object from the parts where the selected objects overlap.
- Union - Combines the selected objects into a single one.
You can also play with nested booleans, that means that you can have boolean objects inside other boolean objects.
Once a boolean object is created you can change the type of operation any time.
Finally, you can use the Merge Geometries function to merge a set of selected objects into a single geometry but with the structure of all the objects retained.