WordPress Core Application Programming Interface, commonly abbreviated as WordPress Core APIs is a collection of several individual APIs and each API covers the functions involved in adding a particular set of functionalities to WordPress. Together, they provide an interface for WordPress developers to write plugins and themes which can interact with the core. ↔️
Using these APIs, you can leave the heavy lifting to WordPress’ Core and be assured that your code is backward-compatible and future-proof.
Now that you have understood what WordPress Core APIs are, you can have a look at the below APIs to understand how to extend the functionality offered by WordPress through plugins.
Following Core APIs, you have learnt in WordPress Development Basics course.
Other Core APIs you need to learn and explore.