Which function key will change a cell reference?

In Excel, the F4 key is used to change a cell reference. When you have a cell reference selected in a formula and press F4, it toggles between absolute (e.g., $A$1), relative (e.g., A1), and mixed (e.g., $A1 or A$1) references. This allows users to easily adjust how the cell reference behaves when the formula is copied or moved to other cells.