Confused by this?
I have a Bible app with 1302 languages you can read in. Amongst the translations are Hindi (Devanagari) Hindi (Latin script), Urdu (Devanagari) Urdu, and Urdu (Latin script). My question is what is the difference between Hindi Devanagari and Urdu Devanagari and why do they both have Latin alphabet versions?
Though Hindi and Urdu are both indeed registers of the same language (Hindustani) which means they share the same grammar and structure, they've taken different standardization paths over the last couple of centuries which has only been accelerated following the independence/partition of India and Pakistan.
As Zerenei says. the difference between them mainly centres on the vocabulary. Hindi takes much of its modern vocabulary from Sanskrit while Urdu from Persian (followed by Arabic). If you take a single sentence written in Latin script, it may be difficult to identify the language as Hindi or Urdu but given a large enough paragraph, the etymological origin of the majority of words will point you one way or another. Apart from this, the fact that the two traditionally use different scripts introduces minor variation in pronunciation etc. The different scripts also serve to keep the languages distinct even in areas of India where the two languages coexist.
Hindi and Urdu are two very closely related languages, most of the time if you speak one, you can understand the other, Hindi is Indian and Urdu is Pakistani. Latin script is what you're reading and typing in right now, devanagari script is देवनागरी and Urdu script is اردو
Hindi and Urdu aren't the same language, they are mostly the same, but there's like 15% of words that are different between the two. And natives do use Latin script, more so now in the digital age, keyboards are primarily in English, so it's easier to just type the word in English script than to find a Devanagari keyboard, many people feel more natural reading Hindi or Urdu in Latin script than in Devanagari.