Per Olivier, here is my suggested edit for the Help entry “Cell Edit Mode.” What do you think?
The cell edit mode displays the formula used by a cell instead of the results generated by the cell’s formula.
Also, the mode highlights the cells that are used in the target formula with system-selected colors. The user can change the cells used in that formula by selecting and dragging the area defined by the highlighted cells. The formula is automatically updated as the defined area is extended.
For example, a cell with formula =A1+B1 displays A1 in color 1 and B1 in color 2 (colors are defined internally). The cell A1 is highlighted in color 1 and B1 is highlighted in color 2.
Press Enter to end the cell edit mode.