Curry is the English description of any of a general variety of spiced dishes, best known in Asian cuisines, especially South Asian cuisine. Curry is a generic term, and although there is no one specific attribute that marks a dish as "curry", some distinctive spices used in many, though certainly not all, curry dishes include turmeric, red pepper and cumin. The word curry is generally believed to be an anglicized version of the Tamil word kari. It is usually understood to mean "gravy" or "sauce", rather than "spices". [1]
It should be kept in mind that the curry served at Indian restaurants in Western countries is not the same as the staple diet for an average Indian family. While retaining similar ingredients used in these restaurants, curries prepared in South Asian homes are considered leaner and healthier by people from these parts. Also, it's incorrect to assume that curry is the most important constituent of a South Asian meal. Indian cuisine, in fact, is one of the most diverse cuisines in the world, and curry is just a part of it. That being said, curry's popularity in recent decades, has spread outward from the Indian subcontinent to figure prominently in international cuisine. Consequently, each culture has adopted spices in their indigenous cooking, to suit their own unique tastes and cultural sensibilities. Curry can therefore, be called a pan-Asian or global phenomenon, with immense popularity in Thai, British and Japanese cuisines.[2]
http://en.wikipedia.org/wiki/Curry