CONTEXT:
I am building an app with Expo React Native. I am done with front-end and now I am working on/learning how to build backend.

I am learning a course on Node.js/Express.js right now, but so far it's been mostly about web stuff (routes, views) that I already have in my React Native front-end.

To my understanding so far, it feels like it is enough for me to have a database to add, get(fetch) and update stuff in it.

QUESTIONS:

-- Will I ever need to use HTTP requests and REST APIs for my app?

-- Even for authentication, it feels like that I can just check if data entered by the user matches the data in the database and that way just authorize the access. Is that right?

____________________________________________________________________________________________________________

I am probably sound stupid. There are so many things that I have been looking up (JWT tokens, HTTP requests, OAuth etc.). I know they are random, that's why I need your help to sort everything in my head into their own shelves and starting working.

PLEASE, PLEASE, PLEASE explain it to me in any way you want. I am not a dummy, I will easily grab your explanations.

It is just I cannot find a good pathway to follow to build a full app. Yes, there are YouTube videos, but they rarely explain why they are doing what they are doing, they are plainly typing their code for the sake of showing their result.