What is the name often given to the 25,000 or more islands spread across the Pacific Ocean?

Pacific Islands?

Yes.

https://www.britannica.com/place/Pacific-Islands

Yes, you are correct! The name often given to the 25,000 or more islands spread across the Pacific Ocean is the "Pacific Islands." The Pacific Islands include a vast number of islands located within the Pacific Ocean, spanning from the western region of the Pacific, near Southeast Asia, to the eastern coast of America. They are known for their diversity in cultures, languages, and ecosystems.