Toggling Cell References: When you're entering or editing a formula, pressing F4 toggles between different types of cell references: Absolute Reference ($A$1): Both the row and column are fixed. Mixed Reference (A$1 or $A1): Either the row or the column is fixed. Relative Reference (A1): Neither the row nor the column is fixed. This is particularly useful when you want to lock certain references while copying formulas across cells.