For the equation e=mc^2

 

which energy is it referring to, I have read that nuclear binding energy is the energy difference between a nucleus as a whole and the separate components = deltamc^2

 

so has the energy of the actual matter which i think is a form of energy actually been used/converted to energy or is it simply some abstract thing we call "binding energy"

The important point is the relationship between mass and energy (the form of the energy is less important).

 

In this example, the greater binding energy of the nucleus leads to the nucleus having greater mass than the individual components.

For the equation e=mc^2

 

which energy is it referring to, I have read that nuclear binding energy is the energy difference between a nucleus as a whole and the separate components = deltamc^2

 

so has the energy of the actual matter which i think is a form of energy actually been used/converted to energy or is it simply some abstract thing we call "binding energy"

 

Yes, it has actually been converted to some other form of energy. That's what's happening in fusion and fission — the binding energy of the system increases, and KE is given to those particles, gammas are released, etc.

 

Binding energy is analogous to ionization energy for an atom, if one were to remove all the electrons. Since nuclear processes are involved, nuclear binding is several orders of magnitude greater than atomic (given in MeV vs eV)

[...] so has the energy of the actual matter which i think is a form of energy actually been used/converted to energy or is it simply some abstract thing we call "binding energy"

 

It's the attraction due to the strong force minus the repulsion between the positive charges. If a nucleus were created from protons and neutrons, the strong force would release energy (and the electric repulsion absorb some), making the nucleus lighter and releasing energy as gammas, expelled quick neutrons, neutrinos...

 

The nucleons are lighter (though it's inherently difficult to attribute energy to one or an other) because of the released energy.

 

This is not restricted to nuclei nor to the strong force. Any form of energy makes objects heavier. Nuclear energy is concentrated enough that its effect on the mass is rather easy to observe and to use in computations.