it's Simple .. For example .. english is not like frensh...but both of them are written with Latin alphabet.. it's the Same like arabic , farisi ...etc...

Arabic language belongs to simitic language family (Afro-Asiatic),but Pesian and urdu are Indo-European language .But of course they have a great influence on each other as an example : Arabic ,Persian & Urdu are written in the with the same style of alphabet , on the other hand the pronunciation of some letters is different & the meaning of a lot of word is also different.

its all alanguge write by arabic alphapet but diffrent that arab r semtic languge n ordo n persian from endo-euro languge but after islam grow alot of arabic word enter to those languge

there are a big different