The Insert Comment command enables you to add comments to your worksheets. Adding comments is useful if you are going to share your work with others. Some explanation might be necessary to clarify certain portions of a worksheet or workbook. Adding comments is also helpful for tracking your work or tracing your footsteps if you are using complex formulas and references. Comments enable you to remind yourself of how a portion of a worksheet operates and to insert questions or comments for others to read.
In the next To Do exercise, you add a comment to explain the data in a cell.
Select the cell for which you want to enter a comment; in this case, select cell B4.
Choose Insert, ...