While building reports it is possible to define multiple categories (buckets) used to group report values. They allow you to sort, analyze, and summarize records based on the values of Text Fields, Numeric Fields, or Picklist Fields. You can add up to five bucket fields per report.
Example: In a report listing the accounts by activity sector, graphical analysis is useless given the number of bars. It is possible to create buckets grouping the accounts together according to economic sectors (Primary Sector, Secondary, Tertiary, etc …) and thus have a synthetic analysis of the accounts.