Order by is clause which is used in SQL database query to specifies that when we use Select statement which returns a result set with the rows in the sorted values of one or more columns. The sort criteria do not have to be included in the result set. Order by is the only way to sort the rows in the result set in the sorting form Without using this Order by clause all the relational database system may return the rows in any order which is not suitable for right information. So that if we wants to required information in the ordering form then you must used Order by in the SELECT statement sent by the application. By using this Order by clause we can got information according to your requirement by further sub queries.