The "Add Notes" field type can be used to display long descriptions in your form, to help your users while filling out the form. It provides a better layout and some rich text formatting options that other fields don't provide. The text entered in a add notes field will be displayed only in the Form and will not be rendered in the View. For example, in the "IT Inventory" form given below, the fields are grouped under different headings with the help of the Add Notes field.
Refer the sample application Display Custom Error Messages to learn how to display customized text in a Note field, based on user input to your form. The script modifies the content of a Note field when a client-side event happens.