Stop Apple photos going to Google photos from my Apple devices

How do I stop photos on my Apple devices (Mac/ipad/iphone/icloud) going to Google photos?

It fills up my Google storage that I seldom use (I use iCloud). If I delete photos from Google, it also removes them from my Apple devices. I never signed up for Google storage. After removing unwanted photos from Google it fills up again immediately, from my Apple photos as well as my wife's Apple photos from a separate Mac/ipad/iphone/icloud. Google only tells how to turn this process on, not turn it off (Google syncing and backup is turned off, but this continues anyways)