Answer 1

They are the maximum and minimum normalized limits of the fundamental data type structure 'float' in C and C++.

They are found in the header <cfloat>(float.h) and are simply intended for use as constants.

FLT_MIN = 1.17e-38
FLT_MAX = 3.402e+38

For more info on the header:
www.cplusplus.com/reference/cfloat/