What is the primary function of conditional formatting in Excel?

The primary function of conditional formatting in Excel is to apply formatting based on specific criteria. This feature allows users to set rules that dictate how cells are displayed depending on their content. For example, you can format cells to change color when a certain condition is met, such as highlighting all values above a specific threshold in red or green. This capability enhances data analysis by providing immediate visual cues, making it easier to interpret data trends and identify outliers.

In contrast, simply making spreadsheets visually appealing, while a potential byproduct of using conditional formatting, is not its primary purpose; it's more about functionality and data insight. Preventing data entry errors is an important aspect of data management but is not directly related to the role of conditional formatting. Additionally, creating targeted advertisements falls outside the realm of Excel functions and is unrelated to the application's capabilities.