Difference between `tkzDefShiftPoint` and `tkzDefShiftPointCoord` in `tkz-euclide`

So I was reading through the tkz-euclide documentation and I saw two different commands being used in a similar manner on examples 4.2.2 and 4.2.3.

• tkzDefShiftPoint
• tkzDefShiftPointCoord

Both commands seem to take the same types of arguments and their difference(s) don’t seem to be explained in the doc.

I copied the code for the second and I switched the commands around, looking for any output differences.

% Original code from doc.
begin{tikzpicture}[scale=1]
    tkzDefPoint(0,0){A}
    tkzDefPoint(30:3){B}
    tkzDefShiftPointCoord[B](10:2){C}
    tkzDefShiftPointCoord[A](10:2){D}
    tkzDrawPolygon(A,...,D)
    tkzDrawPoints(A,...,D)
end{tikzpicture}

% Edited code with tkzDefShiftPoint used instead.
begin{tikzpicture}[scale=1]
    tkzDefPoint(0,0){A}
    tkzDefPoint(30:3){B}
    tkzDefShiftPoint[B](10:2){C}
    tkzDefShiftPoint[A](10:2){D}
    tkzDrawPolygon(A,...,D)
    tkzDrawPoints(A,...,D)
end{tikzpicture}

But the output for both tikzpictures are pretty much the same.

May I know what the differences between both commands are?