An API (Application Programming Interface) is a set of functions that allows applications to access data and interact with external software components, operating systems, or micro services.
APIs are the little pieces of code that make it possible for digital devices, software applications, and data servers to talk with each other, and they’re the essential backbone of so many services we now rely on.
They work as the middle man, allowing developers to build new programmatic interactions between the various applications people and businesses use on a daily basis.
APIs are broadly accepted and used in web applications. There are four principal types of API commonly used in web-based applications: public, partner, private and composite. In this context, the API "type" indicates the intended scope of use.
Public APIs are the most common examples when you think of what exactly an API is. These range from the common apps to feature-rich examples that businesses are built on, including . On the other hand, private APIs are internal applications designed for a specific audience and user base. It’s important to know the difference between the two, as each can be advantageous within an enterprise.
When you think about public APIs, the key word to remember is open. Public APIs are designed to be shared with the outside world. External developers can build applications to take advantage of the capabilities within these APIs. It is important to note that some companies only provide semi-public access by not offering public documentation and allowing developers to submit their app for approval.
Private APIs are often used within an enterprise to improve collaboration. While the API itself is also open as a public API, the difference is it is only open to those that have been granted access. Developers within an organization can take advantage of the functionality from the private API to design and build applications inside the company. Private APIs can leverage existing functionality of enterprise applications so company employees can communicate more efficiently.