It's the difference between having only a basic typeface for Arabic and having software that can properly layout Arabic right-to-left, properly handle the varia

It's the difference between having only a basic typeface for Arabic and having software that can properly layout Arabic right-to-left, properly handle the variant letter forms, and generally formatting the text correctly. There's Arabic the core 28 letterforms and there's Arabic writing with proper initial, medial, and and final forms, collation, and presentation on the page.