I used to think that Node was only used in the server-side app because of the use of the npm command and the ensuing generation of the node_modules folder.
But I noticed that CRA also uses node, so does that make the front-end a Node app?
I appreciate any clarity on this!
Are you talking about the resultant web application created by CRA? No, it's not a Node app. It's a web app. It doesn't need Node. The resulting development environment uses Node as the backend http server. For production generally any http server can be used.