A spreadsheet term.
Some spreadsheet applications such as Excel, lets you click on a cell (the 'active cell') and you can see the formula that created the data you see in the cell. This appears in the formula bar above the sheet itself.
You can then edit the formula, if you wish to change what appears in the active cell.
For example a cell that adds 1+2 would have the formula '=1+2' in the formula bar. Should you want to add 1+3 then you can edit the formula directly from the formula bar.
Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Formula bar