Success Message: After form submission one can see the success message “Your form has been submitted successfully.” For example: “The form has been successfully submitted” or “We will contact you in 24 hours” etc.
Success message works on both form submission and field validation. Based on the condition you can show custom success messages.
Error Message: If you have any conditions to meet when a form has been submitted or edited. If the condition does not satisfy fully then you can show the error message. For example: “Cannot but less than five pieces” or “Delivery price outside USA is more than $50” etc.
Error message works on both form data submit and on field validation. Based on the condition you can show custom error messages.
Notice : If you create multiple Success/Error messages then the last created message will be work first. Also you can use workflow for showing specific Success/Error message.