It is frequently asked about the difference between the above mentioned operations. It's indeed simple. Lets take the example of a cylinder and a box that you want to join together.
The \b fuse operation will make a <b>single solid</b> from the two given solids. It allows you to build complex models by putting simple shapes together.
The \b partition operation will also allow connecting the two solids but it will <b>keep a face at the frontier</b> (in brown on the picture below). The resulting shape will consist in <b>two connected solids</b> that share
a face at their frontier. It means that this face is present only one time in the resulting shape and is a sub-shape of both the box and the cylinder.
\n This operation allows you to identify different areas in a shape (e.g. different materials) and to ensure a <b>conformal mesh</b> when meshing it later. Indeed the face at the frontier is meshed only once.
When you build a \b compound by using the build -> compound operation you just make <b>an object that contains the two separate solids</b> like in a "bag".
The two solids remain unconnected. The compound is just a set of shapes, no more.
