Why there is two differents wordpress API?

I'm developing an application that needs to connect to the API of my Wordpress site hosted by Wordpress.com. I need to create custom posts and modify user emails. I've found two ways of using the Wordpress API: with basic authentication => http://mywebsite/wp-json/wp/v2 ; by creating a wordpress application and using Oauth => https://public-api.wordpress.com/rest/v1.1/sites/mywebsite (doc: https://developer.wordpress.com/docs/) With the first method, I wasn't able to add custom fields to my post, and with the second, I wasn't able to update the email of a user. Could someone please explain the difference between the two and their usefulness?

You can tell by the domain of the API to where it belongs. The latter API is unique for wordpress.com account and might have also access to the WordPress website. The first API is your standard WordPress website REST API. You should be able to update email of user using the REST API if indeed he was registered to your website, as opposed to wordpress.com. Use the Users endpoint.

February 4, 2024