How is react usually used on the site?

Question

React

I'm learning react and while writing simple lists, calculators, etc. to understand and deal with the interaction of react and redux . I
don't understand how to use react on the site yet. At the moment, I imagine it as a tall house with windows. Like the brick component of the house is the usual html, and the windows of the house are inserts of DOM elements written in react, such as various widgets, smart components, etc. And what is static and does not require changes is pure html
Or do you need to build the entire DOM on React?
Sorry for the noob question, but I want to know

Answer 1

On the "website" you can use react to display some kind of dynamic piece. Or you can make the whole site "one dynamic piece" - then it's called SPA (single page application, single page application).