Many people got confused about both the languages when they watch an indian movie in Urdu language. The main reason for this massive confusion is some misunderstanding of indian people, as they believe that our indian movies are in Hindi but this is not true there are few words of hindi in any of an indian movie.
Urdu is the main language of Bollywood, almost 99% bollywood movies are in Urdu language not in Hindi.
Simply there is a wide difference between both Hindi and Urdu and all the indian movies are in Urdu language. Indians uses same words as Pakistani people uses.