What is the difference between variable valve timing and variable valve lift in Audi engines?

I have heard about variable valve timing and variable valve lift, but I'm not sure what the difference is between the two. Can someone explain the differences and what they mean for Audi engines?

Variable valve timing refers to the ability for the valves in an engine to open and close at different times depending on the engine speed, load, and other factors. This allows for better control of the air/fuel mixture and can improve engine performance and efficiency. On the other hand, variable valve lift refers to the ability for the valves to open wider or narrower, allowing for more or less air to flow into the engine. This can also affect performance and efficiency, and some engines may have both variable valve timing and variable valve lift.