How Does This MACROS Work

I recently took a macros my friend did and adjusted it so it would work for my problem.

It works fine but there is one thing i don't understand about it.

The initial problem was that i needed a macros that could copy a range and paste it 1 cell space to the left and then delete the last cell of that range, so it would look something like this:

FROM THIS:

HIJKLM2NIVEL
3
21
TO THIS:

HIJKLM2NIVEL3
21

so this is the macros i am using which works perfectly:

Range("H1").Select
Selection.End(xlDown).Select
Selection.Offset(0, 2).Select
RC = Cells(Columns.Count, ActiveCell.Row).End(xlUp).Column
Range(ActiveCell, Cells(RC, ActiveCell.Row + 11)).Select
Selection.Copy
ActiveCell.Offset(0, -1).Select
ActiveSheet.Paste
ActiveCell.Offset(0, 4).Select
Selection.ClearContents

What i don't understand is why i have to use the +11 in order for it to move 4 spaces to the right.