API overview \r\n Application programming interface ( API ) is a software design approach that enables software and system developers to integrate with other systems based on a defined set of communication methods. APIs serve as software building blocks and allow for software reuse — essentially allowing fast development of new systems based on existing capabilities. \r\n APIs have existed since the dawn of modern computing and are constantly in use by software libraries and frameworks, operating systems, remote system communications, web applications, and, most recently, mobile applications.   \r\n APIs can be private; that is, for internal use within a system, a company, or between two parties that agree to communicate via APIs. Alternatively, they could be public, which means that the person or company that offers the API makes it available for general use. \r\n A detailed history of APIs in the modern age can be found in the  API Evangelist / History of APIs.…