When the normType is NORM_MINMAX, cv::normalize normalizes _src in such a way that the min value of dst is alpha and max value of dst is beta. cv::normalize does its magic using only scales and shifts (i.e. adding constants and multiplying by constants).
CV_8UC1 says how many channels dst has.
The documentation here is pretty clear: http://docs.opencv.org/modules/core/doc/operations_on_arrays.html#normalize