#Boolean of bodies

Select body A, press the button, click body B. The action — Cut, Union or Intersect — is chosen in the top bar.

#Why it exists separately

The ordinary commands (extrude, cut, hole) work from a sketch: an outline gives the shape. A boolean works with two finished bodies — where the tool is already built as a body rather than drawn as an outline.

That is how you clear a pocket to the shape of a neighbouring part, subtract imported geometry from a blank, or keep the volume two bodies share.

#Three actions

• Cut — the volume of body B is removed from body A. Order matters: A minus B and B minus A are different results.
• Union — the two bodies become one.
• Intersect — only the shared volume is left. Often the shortest way to a complicated shape: two simple bodies overlapped, and you keep the middle.

#What happens to body B

It is consumed: after the operation the timeline holds the result, and the original body B is no longer a body of its own. You can see it in the body list — where there were two, one is left. Delete the boolean node and both bodies come back.

#When it is the right tool

• The cutting tool is itself a body: an import, a primitive, a separately built shape.
• The shape is easier to get by intersecting two simple bodies than from a single outline.

#When it is not

When the shape comes from a sketch. A sketch cut stays tied to its outline: edit the outline and the cut follows. A boolean ties two BODIES instead, so an edit of the original sketch reaches the result by a longer road — through rebuilding both bodies.