A Drill-Down Report, also called an Interactive Report, is a report with more detail. Imagine that you are looking at a Balance Sheet, presented as a drill-down report. The topmost list, also known as the Basic List, contains the top-level information such as current assets, fixed assets, etc., under the grouping assets on one side of the Balance Sheet. The drill-down functionality helps you select a line item from the Basic List (e.g., fixed assets) and drill-down further to a detailed list (secondary list) which displays various components of the fixed assets such as land, buildings, machinery, etc. You may drill-down even further by double clicking the building line, which will bring up the next detailed list and so on.
You will be able to create a drill-down report with a maximum drill level of 20; that is, including the Basic List you will have a total of 21 levels in a single drill-down report.