What does the dollar sign ($) signify in an Excel formula?

The dollar sign ($) in an Excel formula signifies that a cell reference is absolute. This means that when you copy the formula to another cell, the reference with the dollar sign will not change, allowing you to keep a steady link to a specific cell. For instance, if you use a formula like =$A$1 in a calculation, no matter where you copy this formula in your worksheet, it will always reference cell A1. This is particularly useful in scenarios where you need to use a constant value from a specific cell across multiple calculations, ensuring consistent results while performing calculations in different areas of your spreadsheet.

The concept of relative references, indicated by the absence of a dollar sign, allows the cell reference to adjust based on where the formula is copied. The auto-completion feature is unrelated to how cell references are used and does not utilize the dollar sign for function. Lastly, formatting options pertain to how data appears rather than how it is referenced in cells; formatting does not involve the dollar sign for functionality in formulas.