In my lecture notes it is said:
In normal circumstances every atom, of any substance (conducting or not), has an equal amount of positively and negatively charged particles, hence it is neutral. Also, the body made from these particles, is neutral.
Also, free charge is defined as charge that doesn't belong to any atom or molecule, it's free to move and conducting substance is one that has many of these.
How can a substance have free charge, have every one of its atoms in neutral state and not be charged?