Well, I THINK you were asking what that formula does. First of all "" indicates an empty string of text, so the formula is saying IF the cell E9 is not empty (or blank) then return the value which is in cell D9, otherwise return a blank to the cell that the formula is in (i.e. F9). With the dollar symbol in front of the D, then when the formula is copied across the row, it will become:

(in G9): =IF(F9<>"",$D9,"")
(in H9): =IF(G9<>"",$D9,"")
(in I9): =IF(H9<>"",$D9,"")

So, if the cell to the left of the cell_which_contains_the_formula is blank, then show a blank, otherwise show what is in cell D9.

Hope this helps.

Pete