What is the difference between web backend and mobile backend?

Question

Mobile development

I am doing a backend for websites, they suggested writing for a mobile application, what is the difference between a backend for mobile and a backend for the web?
As I imagine:
A request is made to a specific address, for example email, pass, I process it, check the correctness and check with the database, then return the json response. Further, I would write information to the session on the web and would work with the session. And how does it work with sessions? Are there sessions at all? If possible, an article about this. Thank you.

Answer 1

Use API and tokens:
after authentication, issue a token to the user, and write it to the database for yourself.
The rest of the backend is no different from the web backend. That's why it is a backend so that it can be used by many (different) clients.

Answer 2

IMHO, the difference is 0.