As we know we need to check each and every activities through different report and update daily activities.So while accessing these reports we need to give inputs on selection screen otherwise all data will be fetched which we dont require aand also it is time consuming.So there are many ways to select field selections like parameters,select-options,check boxes,radio buttons etc.For example parameters are used to input any single value,where as sselect-options means to input a range of values.