When you select the fields that you want to include in a query and then run it, every record in the database which contains the selected fields would be returned.
In order to make a query more meaningful, it is usual to include at least one parameter (search criteria) in the query. When you run the query, you will be presented with the result that matches the parameter used.
challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Parameter Query