When building a query, you usually do not want to see information on every product you sell. Instead, you want to see information that relates only to a specific product or product line. Similarly, you probably do not want to see this information for every year the product has been available, but only for recent periods.
When you set a filter in the Query section, data is returned from the database only if it meets the specified conditions. For instance, suppose you only want to see customers who spend more than $400,000 per year, or who buy gardening products in the Midwest. By applying a filter you are instructing the database to “give me only the data which satisfies the following conditions” (sales > $400,000; or, state is in Midwest Region and Product Line = Garden).
For example, a filter placed on Item Type (which includes an “=” (equal) operator and value “Keyboard”) returns only records associated with keyboard sales. Records associated with all other products are excluded from the Results set. The data set could be expanded to include modem sales records by adding the value “Modem” to the filter expression.
Similarly, the filter “> 5000” applied to the Amount Sold item filters out all sales transactions less than or equal to $5,000. Alternately, the expression “between 5000, 10000” would exclude transactions above $10,000 and eliminate any below or equal to 5,000.