For years, term "doping" in semiconductor nomenclature meant introduction of alien elements into a given semiconductor material in order to alter its electrical condutivity. For instance, introduction of boron makes silicon assume p-type conductivity while doping with phosphorus makes silicon n-type. And obviously higher the concentration of introduced dopant atoms, higher the electrical condictivity of semiconductor.

These days term "doping" takes on addditional meaning. With a growing interest in an effective control over the electron's spin state (see spintronics) the interest in magnetic semiconductors, i.e. semiconductors displaying  ferromagnetic properties, is also growing. The easiest way to make certain classic semiconductors display some ferromagnetic properties is to dope them with selected alien elements. For instance gallium arsenide, GaAs, will display ferromagnetic properties when manganese (Mn) atoms are introduced into its structure and change it into GaMnAs.

The difference between these two cases of "doping" is that in the former case it takes some 1 atom of dopant per milion atoms of silicon to make a diffference in its electrical conductivity, while  in the latter case manganese doping levels as high as 10% may be needed to see meaningful differences in ferromagnetic properties of GaAs.