Dictionary.net

(Or "drill-down analysis") To examine data ingreater detail, especially, in reporting, to interactivelyselect some item from a summary and display the data thatcontributed to that item, broken down by some extra parameter.For example, when viewing your company's total worldwide salesfor each month of this year, you might drill down to seeOctober's sales by country, then again to see October's salesin Afghanistan by product and so on.This kind of analysis is often supported by some kind of datawarehouse.