The terms Jaguar Brake Rotor and Jaguar Brake Disc describe the same component. The correct term used is dependent on what side of the Atlantic your Jaguar is used on. It is a thing of the English to have their own name for a component on a vehicle like the hood is called a bonnet. They just want to be different.
Immaterial if you chose to call the brake rotor a rotor or disc, it will still be the same part in a braking system. It is the round part with smooth sides that is mounted to the wheel hub in which the brake pads make contact with to bring your vehicle to a halt.
The brake discs or rotors can last the service life of your Jaguar if periodical maintenance is preformed on it when it is needed and before it becomes necessary. This is to say the brake pads have to be regular replaced before they wear totally out. When this is not done and the brake pads wear totally out, the metal backing plate they are mounted too comes in direct contact with the brake rotors. This causes damage to the brake disc by carving grooves in them. The only way to remove these grooves on your Jaguar is to have the rotors machined down in a procedure commonly called turning the rotors.
If this turning the rotors occurs too often, then too much of the surface on the rotors will be removed and the heat being generated by contact with the brake pads cannot be properly dissipated. This causes the brake on that wheel to overheat which could lead to it seizing up when the Jaguar is in motion.