What is the keyless entry system on the Audi A6 and how does it work?

I am currently looking to purchase an Audi A6 and I keep seeing references to a 'keyless entry system'. Can someone please explain what this system is and how it works in the Audi A6?

The keyless entry system on the Audi A6 is a feature that allows you to enter and start your car without using a traditional key. Instead, it uses a small key fob that sends signals to your car to unlock the doors and start the engine. It is a convenient and secure way of accessing your car.