The WordPress API stands for the WordPress Application Programming Interface. It can be separated into multiple API sections / topics. Each covers the functions involved in and use of a given set of functionality.
How do I access my WordPress API?
Accessing all of your site data via the REST API is as simple as composing a URL. For any WordPress site running at least version 4.7, add the following string to the end of your site's url: /wp-json/wp/v2 (e.g., http://example.com/wp-json/wp/v2 ). Put that URL in your browser, and see what comes up.