API is something that we use on a daily basis. It is software that allows interactions between multiple software applications. 

    Example: When you use an app like Facebook, when you send an instant message through it or check the weather on your phone, you’re using an API.



In this section 

                                                                  How does the API work, what is JSON-HA

API Documentation

Woocommerce – Orderadmin plugin

Shopify

Opencart

Amazon