Google DNS Settings

I want to get Google DNS settings entered to my network.
But, when I enter the Google DNS 8.8.8.8 and see the network also the ISPs DNS also comes alongs with it.. Why is that...?
Does Google also requires Local ISP DNS as well along with it or how..?

here is the image below:

View attachment 255995

Can you tell me how to eneter the Google DNS without getting the LOcal ISP DNS along with it..?

Regards

from Google https://ift.tt/3h5v4KW
via IFTTT