How does the parking assist feature work in the Audi A1?

I am considering purchasing an Audi A1, but I am unsure about the parking assist feature. Can someone explain how it works and if it is worth the extra cost?

The parking assist feature in the Audi A1 uses ultrasonic sensors to detect objects in front, behind, and to the sides of your vehicle. It provides audible and visual alerts to help you park in tight spaces with ease.

I have the parking assist feature in my Audi A1 and I find it incredibly useful, especially when parallel parking in busy city streets. It takes all the guesswork out of parking and saves me a lot of stress!