Why is the Audi A8's engine oil important?

I recently purchased an Audi A8 and noticed that the engine oil needs frequent changing. Why is this necessary and how often should I change it?

Engine oil is essential for the proper functioning of your Audi A8's engine. It not only lubricates the moving parts, but also helps to cool the engine and prevent wear and tear. It is important to follow the manufacturer's recommended oil change intervals to ensure the health of your engine.