McGrath - Urdu and Hindi are different languages.
Urdu (from turk. ordu = army, regiment), with Turkic base, is the lingua franca of the big field camps of the Mughul conquest of Northern India, incorporating a lot of words from Hindi, Persian, and other languages of the area.
In Pakistan the share of Hindi words is bigger than in Afghanistan, where Persian has a bigger share.
(Information about 40 years old, when I started my studies.)

Wilfried