INPUT is returned when the action requires more input from the user.
I did not understand the above Point .
(As per my understanding INPUT is applicable when we are doing validation inside the execute Method itself , please correct me if i am wrong)
Can anybody please tell me when should i use return type as "INPUT" inside the execute method of an Action class ??
Generally validation is not handled inside the execute method so you don't need to return input from the execute method. If you use struts 2 validation (info here) or use a simple validate method (example) for your data, then the validation interceptor will validate your data and if there are any validation errors, then the workflow interceptor will automatically send you to the input page...