Filters make your final data set more efficient and manageable by filtering out unnecessary information, since unfiltered data stored on a server can take up many gigabytes. Filters also refine the scope of your reports.
For example, you want to see the quarterly numbers for sales reps in the Southwest. When you build the query, include both Region and Representative items, but filter the Region item to retrieve only Southwest region data. The data in the Results section includes numbers for all the Southwest region reps, which you can compare to the reps' performance. A second filter applied to the Representative item can excludes all reps except those with over $50,000 in sales.
You can see which items in your data set are filtered by displaying the Filter line. Although you may have the same item iconized on both Filter and Request lines, the icons are independent. You do not have to request an item to filter it, or vice versa. You can also apply filters in the Query or Results section. In the Query section, the database filters out filtered values before the data reaches your desktop. In the Results section, filtered values are excluded from the display, but remain in the data set.