React build Application change data source?

Question

I used create-react-app to build an app.

This app had require some image, and this image was used in Home Page

If I just want to change that image in Home Page or some new text change, how could I do?

I don't think it's that simple just re-run build. (or it's just like that?)

I don't have any real world web experience.

I want to know how real server how to do that. I think real website could not be off line even in

second.