explains Absolute cell references. An
absolute cell reference is a cell reference used in a formula which does not
change no matter where it is copied to.
An absolute cell reference is indicated by the use of a dollar sign
before both the Column letter and row number.
The screen shot represents what happens if a cell which uses absolute
references in its formulas is copied to a different location. The cell
reference is unchanged even though the source range has been copied to F3.