A korma is nothing but an Indian name for curry. To be extremely clear about the semantics, a korma is a richer more thicker curry (not runny or thin) which is nicely fried in a good amount of oil (again I am talking extremely traditional versions). The color is nice reddish brown and the gravy is made with lots of onions, tomatoes, yogurt and spices such as ground corrainder, cumin, cinnamon, cloves, black pepper, red chillies etc.
You will see that a lot of recipes will also call for coconut milk. To me however a traditional korma never has coconut milk in it. It's just spins that people have come up with.
I have not tried the product you refer to, nor can I comment on any bottled sauces since I make my own. It's hard to compare these sauces with home made versions. I personally dislike any readymade curry sauces - even the thai ones are pretty bad. I think the spices just don't retain their flavor in a bottle very well. Again strictly my opinion, I am not commenting on the convenience factor, it's more a taste factor.