API documentation is basically a comprehensive guide that explains how the API functions, how it is structured, and how it is used. It is a documentation used by developers and other stakeholders involved in the API and needs to understand how it works and also to use it effectively. For this, API documentation usually offers information on accessible endpoints, input, output parameters, error codes and other details if need be. It has become necessary to increase team cooperation and communications as well as promoting the effective implementation of the API-Design First approach.