drill-down
Reports that display all their data at once may not be convenient to
		use. With drill-down you can display an overview of the data but give users the ability to
		reveal further layers of data as required. For example, one user may be interested in seeing
		sales of a particular product group or individual product in all years. Another may be
		interested in seeing sales of all products in a particular quarter or month. Each user can
		drill-down through the products or years to see only the data they require. You drill-down
		by expanding and collapsing the tree structures of the lists containing the data.