How can an app interact with a Wordpress site?

Question

iOS

Hello.
There is a site with content (posts, variables in them, etc.). There is an app for iOS.
How can I establish interaction between WP and iOS so that when requested from an application, WP generates a JSON response?
I don't know much about this, sorry if the question is wrong.

Answer 1

https://developer.wordpress.org/rest-api/