Core Balance Current Transformer and Current Transformer both are same or diffrent?

 

As I understand it, a core balance transformer has 2 "primary" windings connected so the current in one counteracts the other so the magnetic fields cancel out ensuring no output results in the secondary when both currents are equal. Then if one current is different from the other, like Active and Neutral currents when there is a path from Active to Earth, so the Neutral current is now less, there is a magnetic field produced and an output is produced in the secondary.
A current transformer usually has only one primary and one secondary winding.