PURPOSE Conditional formatting automatically highlights cells that meet certain rules. COMMON USES Highlight overdue dates, duplicate values, negative numbers, high-priority items, blank required fields, or values above a threshold. STEPS Select the data range, create a rule, choose the condition, and apply a readable format. BEST PRACTICES Use simple rules and consistent formatting. Too many colors can make the spreadsheet harder to understand. CHECK Test rules with sample data to confirm the correct cells are highlighted.