Presented below is an introduction to formula cell reference notation.
The Microsoft Excel A1 reference style or R1C1 reference style is the notation used to identify cell positions in formulas.
Excel allows an individual to use two types of cell reference styles to identify a cell’s position, A1 and R1C1 reference styles. These styles are controlled by adjusting the controlling options of Microsoft Excel. The A1 reference style is the default reference style for Excel. To tell if the A1 reference style is in use, look at the column headers of a worksheet. If letters appear for the column headings, the reference style for Excel is currently A1. In this mode, cells are referenced using a letter for the column and a number for the row. The picture below demonstrates this concept where the selected cell would be referenced as A3.
To tell if the R1C1 reference style is in use, look at the column headers of a worksheet. If numbers appear for the column headings, the reference style for Excel is currently R1C1. The picture below demonstrates this concept where the selected cell would be referenced as R3C1.
Whatever reference style mode Excel is in, all cell references typed in formulas must be in that reference style form. If not, an error will be generated. The A1 reference style is the easiest to use in Excel. It is recommended that the designer use this style when constructing formulas. To change between the two reference styles, consult Excel on-line help by pressing F1.