Cells in which you can enter data have a icon in them. As their name suggests, you are free to enter data in these cells. You can also create Excel formulas in these cells if they do not contain some already.

Protected cells are listed in the cell's information dialog box. You cannot change these cells. You cannot enter data in them or link comments to them. You can only consult them in read-only mode.

The protection cannot be removed from these cells.