Kenneth S. Krane, Introductory to Nuclear Physics, defines mass defect as Δ=(m(A,Z)-A)$c^2$, where m is the mass of the nucleus with atomic number Z and mass number A and he says that given Δ, we can use the nuclear binding energy to deduce the atomic mass, where the nuclear binding energy is:
B=(Z$\times$mH+N$\times$mn-mA)$c^2$ , where mH is the mass of Hydrogen, mn is the mass of the neutron and mA the mass of the nucleus with atomic number Z, mass number A and N neutrons. But Wikipedia says the following:
"The mass defect of a nucleus represents the amount of mass equivalent to the binding energy of the nucleus (E=m$c^2$)"
So, what is the mass defect? The definiton from Krane's and Wikipedia's don't seem equal to me, honestly Krane's definition seems random me. Are these 2 statements equivalent? And how can the mass defect be used in the nuclear binding energy equation to deduce the atomic mass?