this is the structure of the node api end point and how the file are organized
node backend connected to relational database mysql 8.0
controller/postController.js >>> the absraction layer that performs crud of Posts, the return json file __ DataAccess layer.
routes/posts.js >>> the API endpoints called by the client application, perfomr all client request (get, post,put,delete)
the folder with react app, this is the front end client application