Introduction to Autosubmit and Partial Page Refresh

You may want to trigger an autocomplete rule where the field value is instantly updated on the underlying business object.

Since Autocomplete Rules works on the data model layer, the tool can't detect a change of value in the field until the business object receives the value from the UI. But many fields in the responsive pages aren't instantly updated on the underlying business object for performance reasons. You need to configure the Autosubmit and Partial Page Refresh properties using Page Composer for efficient functioning of the Field Modification and Field Validation rule types.