What is conditional formatting used for in Excel?

Conditional formatting in Excel is a powerful tool used to change the appearance of cells in a worksheet based on certain conditions or criteria. This means that when specific rules are met, the formatting of the cell can adapt, allowing users to quickly identify trends, highlight key data points, or visualize information effectively. For instance, you could set a rule that turns a cell red if a sales figure falls below a set target, or highlights a budget cell in green if expenses are under budget. This functionality helps in drawing attention to important insights or potential issues within the data, making it easier to analyze the information at a glance.

The other options do not align with the primary purpose of conditional formatting. Printing worksheets refers to making physical copies of the data for sharing or presentation. Securing workbooks with passwords involves protecting sensitive information but doesn't relate to how data is visually represented. Sorting data alphabetically is a method of organizing information, but it does not involve changing the formatting based on specific criteria. Hence, the correct answer highlights the distinct capability of conditional formatting to enhance data visualization based on conditions.