What is Instagram Private API and what is the difference between Public API?

Question

API

In the course of working with the public API of Instagram, I find links to a certain Private API of Instagram.
What is Private API and what is the difference between Public API?

Answer 1

it's just emulation of mobile application requests

Answer 2

The private API is used in the Instagram mobile app.
For example, the following queries refer to it: accounts/login, media/upload, media/configure