In asp.net RequiredFieldValidator What is difference between Text and ErrorMessage?

Text : The message to display when validation fails.

ErrorMessage : The text to display in the ValidationSummary control when validation fails. Note: This text will also be displayed in the validation control if the Text property is not set.

Ref : http://www.w3schools.com/aspnet/control_reqfieldvalidator.asp

The ErrorMessage property shows up in the ValidationSummary control. Text shows up next to the controlToValidate. If you set the Display property as None the Text won't appear.

In a normal setup, the text property is displayed next to the validator and the error message is displayed in the ValidationSummary.