The JF-17 Thunder is a fighter jet which has been developed with the joint collaboration of Pakistan and China. There has been a lot of hype about this aircraft in recent years. Pakistani and Chinese authorities are aggressively searching for customers for this aircraft. Recently they have got some orders from an Air Force of an undisclosed Asian country.
Is the JF-17 merely an upgraded Mig-21/F-7 (like Mig-21 Bison), or is it a whole new aircraft?