Each cell in an Excel spreadsheet can have unique formatting for things such as font, number formatting, color, borders, and alignment. Conditional formatting allows formatting for cells to vary based on data in the spreadsheet.
See also Excel rounding and precision.
Conditional Formatting allows the formatting of color, font effects, background color, etc. of cells on the spreadsheet to vary based on the cell's value, or other cell's values. A range of cells can have mini-charts or different icons in the cells based on their values.