Creating a Joint on a Screwdriver...

[SonOfLiberty796]

The body is the green geometric shape you apply in the model editor so you are able to grab the screwdriver Parent and child body is 2 different bodies that you in the joint options you add the body of your choice as the parent and the other body as your child, I think YourComputer can explain this a bit better than me ^^

Ok I understand the first sentence... as for the parent and child body thing... huh? :p