can anyone help me in this RF code?

GapCurrent = sum(output(Index).*geom.EdgeLength(Index)');
Impedance = GapVoltage/GapCurrent;
Resistance(m) = max(real(Impedance), 0);
Reactance(m) = imag(Impedance);
GAMMA = (Impedance-50)/(Impedance+50);
S11(m) = 20*log10(abs(GAMMA));
VSWR(m) = (1 + abs(GAMMA))/(1 - abs(GAMMA));
FeedPower(m) = 1/2*real(GapCurrent*conj(GapVoltage));
frequency(m) = f_re;


i get this code in a e book but it did not explain to me about the code
it was a matlab code
i wanna ask for: FeedPower(m) = 1/2*real(GapCurrent*conj(GapVoltage))
what is the meaning for the "real"?

VSWR(m) = (1 + abs(GAMMA))/(1 - abs(GAMMA))
and what meaning is for the "abs"?

thanks for help

"real" is taking the real part of the argument
"abs" is taking the magnitude of it. Z = R +jX, so abs(Z) is square root of (R^2 + X^2)

thanks for your help MI3talk