SAP Fiori has a wide range of advantages over SAP GUI, including improved workflows for flexibility and multi-device tasks. Fiori offers you the benefit of RESTful APIs in architectural terms, which are more flexible and easily linked than conventional SAP application integration tools. Fiori is set to replace the SAP GUI in the organizations that are migrating to S/4HANA. This is mostly the result of an overall better UX, developed to improve the new database. The older GUI is relatively lightweight and hard to use (or train). HTML5 is developed for Fiori. As a result, from a modern mobile app, it has the sort of smooth gestures and controls you expect. In design, the displays are quick and clean, matching what consumers expect from today's apps.