Conductor or Insulator?

A conductor allows electrons to move freely and an insulator blocks their movement. In this video, I test several different objects to see if they are insulators or conductors.
For example, is a pickle a conductor or an insulator?
I answer these questions by hooking up an electrical current.
Is copper a conductor?
Is wood an insulator?
Plastic Conductor or insulator?
Aluminum Insulator or not?