The code allowing two applications to share information is called an application programming interface (API). Various multimillion giants like Amazon, Facebook, and others have their established APIs. They help the companies to access some of their information without letting entirely access their ecosystem. This paradigm has given rise to what we know today as the API economy. APIs basically help in improving the interoperability of any system. A series of automated trading platforms can be connected with the help of APIs, thereby helping the traders obtain real-time pricing data.

APIs are of four different types. The public API is open to the public and is used by both businesses and developers. The partner API aids in business to business interactions. Internal APIs are completely meant for the internal use of a corporation and the composite API is an integration of two or more APIs. This helps them to provide interdependent processes.

The major use case of APIs is to help the developers leverage the existing functionality of infrastructure rather than building them from scratch. This helps the developers save a lot of time and money.