There are Audi CV Axle Shafts on all vehicles of this automaker that have power to the front wheel assemblies. This is a flexible joint that makes it possible for the front wheels to have the ability to turn and still be capable of supplying power to the wheel for forward motion.
A visual inspection of the CV axle shaft is not always possible because it is partially hidden from view by the CV boot on the drive train of your Audi. This is a good thing for an owner to observe. If the CV boot is ripped or its containment breached is the time for the owner to know they have to make repairs on their vehicle soon to keep it in operating condition.
The end of the Audi CV axle shaft is half of the CV joint. This is basically a set of U joints that are joined together so power can be transferred from the transmission to the wheels assemblies. If there is any wear on this connection, the driver of the Audi will be able to feel it in the steering wheel. This will be a jarring feeling when the Audi is placed into gear. The jarring is from space in the CV axle shaft with the adjoining U joint. If replacement of the CV axle shaft is not on the repair list for your vehicle, it should be before the wear damages other components in your drive train.
The replacement of the CV axle shaft required the entire wheel assembly to be dismantled. This is a complicated and time consuming repair procedure, but the owner can complete it if they are mechanically inclined and have an afternoon to spare on their busy schedule.