SOLIDWORKS-AUTOCAD-UNIGRAPHICS DESIGN With tutorial aids that very simple and funny, which emerge to learn 3D design in learner friendly way

In the Solidworks program we can combine the bodies contained in one multibody section. We will not be able to combine two separate parts, not touching.
We can create a multibody section by using Insert Section to place one section in another section file.
Then we can only use Combine on multibody parts.
To use the Subtract combine in Solidworks
Click Combine the Features toolbar, or click Insert, Features, Combine.
Combine PropertyManager will appear.
In the Operation Type, click Subtract.
In the Main Body, select the body that will be maintained as the main body.
For Main Body, select the body to keep. ...
For Bodies to Subtract, select the bodies whose material you want to remove.
or select a body of solid body design FeatureManager folder tree.
Under the body to Subtract, select the bodies which we want to remove for Solid Bodies.
Click Show Preview to see the feature.
if it is appropriate ..... Click OK.

good luck