DC_CAL measurement

What’s the function of the following code? What is the difference between motor.DC_Calib_ and motor.current_meas_? Anyone can help?

// DC_CAL measurement
if (hadc == &hadc2) {
axis.motor_.DC_calib_.phB += (current - axis.motor_.DC_calib_.phB) * calib_filter_k;
} else {
axis.motor_.DC_calib_.phC += (current - axis.motor_.DC_calib_.phC) * calib_filter_k;
}

Solved!