What is an API?
Application Programming Interface (API) is a software application that provides a point of interaction between a service and an application. For example, the Facebook mobile application uses an API to communicate with the Facebook Databases to load your profile, messages and other peoples posts.
What Do They Send?
The two most common formats for API’s to use are JSON and XML, both can be used to represent structured data and different data types.
Key point: APIs enable solutions to be developed that provide better experiences for consumers without dramatically raising the cost. They can also streamline operations for companies.