What is useDeferredValue in React 18, how does it keep UI responsive for expensive derived computations, and when should you prefer it over useTransition?

Imagine you're coloring a picture and you want to add lots of tiny details. If you try to do it all at once, you might get tired and slow down. useDeferredValue is like saying, 'I'll finish the big parts first, and then add the tiny details later when I have more energy.' It helps your computer stay fast by doing the most important work first.