The cover makes no sense at all. It's a random shot from the game that doesn't even remotely fit into the plot of the book.

The elves were the original settlers of the continent before things got complicated. They retreated to the mountains where the elders hope the humans will let them be. The hotblooded youngsters war against the humans and I think there are still some that live in human towns, though very much treated as second class. It is also implied that Ciri, the princess, has a distant line of elvish blood.