From this little (familiar) box you can change the formatting that you applied in the first place.
If you keep the ‘Specific text’ you can decide here whether the cell should contain, not contain, begin with or end with the text that you enter in the field to the right.
This means that the formatting applies when a cell is empty or, for example, holds a value greater than, or less than, 100. Here you edit your rule so it no longer “triggers” on a cell containing specific text, by choosing “Blanks” or “Cell Value”.
If you keep the ‘Rule Type’ you can change the “ trigger” of the formatting.
You can also make the rule more advanced by basing it on a formula. If you don’t want the conditional formatting to apply when “something” happens in a cell, you can change it to apply on all cells and filling them with color based on their value compared to the average of the data.