Curd and Yoghurt are indeed used interchangeably in many parts of (mostly urban) India and the region in general, though probably not in the UK, the US and some other parts of the world.
We will spell out the benefits of Yogurt.
But there is a difference between curd and yogurt/yoghurt (used in UK).
Yogurt (plain yogurt from whole milk) is 81% water, 9% protein, 5% fat, and 4% carbohydrates, including 4% sugars (table). A 100-gram amount provides 406 kilojoules (97 kcal) of dietary energy.