Computer Dictionary of Information Technology

drill down

(Or "drill-down analysis") To examine data in greater detail, especially, in reporting, to interactively select some item from a summary and display the data that contributed to that item, broken down by some extra parameter.

For example, when viewing your company's total worldwide sales for each month of this year, you might drill down to see October's sales by country, then again to see October's sales in Afghanistan by product and so on.

This kind of analysis is often supported by some kind of data warehouse.