An acronym API stands for the Application Programming Interface. It’s a special class of software or a set of protocols or set of routines that enable interaction between different applications.
APIs are available on all most all platforms and support all devices. These are generally small server-side application, deployed in the form of a micro-service and can be hosted on any platform.
The application programming interface enables the interaction between the application hosted either on the same platform or on a different platform. It also enables the secure exchange of the data between different systems.
All APIs are not Web Services. However, all Web Services are termed as APIs.
APIs help in creating the decoupled and reusable building blocks that can be used in software development. The below API flow diagram highlight the basic architecture of an API.