Conditional formatting is a powerful tool in Excel that allows you to automatically change the appearance (formatting) of a cell based on certain conditions you define. It helps you visually identify patterns, trends, and exceptions within your data set.

Here's a breakdown of what conditional formatting does:

* Rules: You set up rules that specify the conditions for formatting. These conditions can be based on values, text content, cell formatting, formulas, or a combination of these.
* Formatting: When a condition is met, the formatting you define (e.g., font color, fill color, borders, data bars) is applied to the cell.
* Visualization: Conditional formatting helps you see important information in your data at a glance, without needing to manually analyze each cell.

For example, you can use conditional formatting to:

* Highlight cells with values above or below a certain threshold (e.g., red for negative numbers, green for positive numbers).
* Apply color gradients to show data trends (e.g., a color scale from green to red representing increasing sales figures).
* Use data bars or icon sets to visualize data comparisons within a row or column.

Conditional formatting makes your spreadsheets more informative and easier to understand, especially when dealing with large datasets.