Hi y2k1981,
The differenec between the two properties is in the reference style used. If you don't know the difference I suggest you review the Help, but briefly ..
A1 style references use letters for columns and R1C1 style references use numbers.
A1 style references are absolute and R1C1 style references can be relative.
To see the difference, put a simple formula in a cell, for example in cell A2 put "=A1"; switch to formula view (<CTRL><`>) then use Tools > Options > General > R1C1 Reference style to switch between the two styles.
Enjoy,
Tony